Light-emitting module and lens

ABSTRACT

A light-emitting module includes: a first light source unit including: a first light source, and a first lens on which light emitted from the first light source is incident; a driver configured to rotate the first lens; and a controller configured to, conjunctively with the driver, control an output of the first light source. A central axis of light emitted from the first lens is oblique to a rotation axis of the first lens. The controller is configured to control the output of the first light source according to a position along a trajectory of the central axis of the light emitted from the first lens.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a bypass continuation of PCT Application No. PCT/JP2021/045390,filed on Dec. 9, 2021, which claims priority to Japanese Application No.2020-214877, filed on Dec. 24, 2020, Japanese Application No.2021-190792, filed on Nov. 25, 2021, and Japanese Application No.2021-198770, filed on Dec. 7, 2021. The contents of these applicationsare hereby incorporated by reference in their entireties.

BACKGROUND

The present disclosure relates to a light-emitting module and a lens.

A conventional lighting device that has been disclosed includes aplurality of semiconductor light-emitting elements, a housing holdingthe plurality of semiconductor light-emitting elements so that theoptical axes of the light emitted by the plurality of semiconductorlight-emitting elements are oriented in the same direction, and ahousing drive means that displaces the housing along a plane crossingthe optical axes. The housing is rotated around an axial centerextending in a direction orthogonal to the aforementioned plane atsubstantially the center of the plurality of semiconductorlight-emitting elements, thereby mixing the light emitted from theplurality of semiconductor light-emitting elements at the imagingsubject, and eliminating unevenness of the color temperature and/orlighting occurring due to the individual differences between the singlesemiconductor light-emitting elements. The light distribution pattern ofsuch a lighting device is constant (e.g., see Japanese PatentPublication No. JP 2005-121872 A).

SUMMARY

The present disclosure is directed to provide a light-emitting modulethat can modify a light distribution pattern, and a lens that is used insuch a light-emitting module.

A light-emitting module according to an embodiment of the disclosureincludes a first light source unit including a first light source and afirst lens, a driver capable of rotating the first lens, and acontroller controlling an output of the first light source conjunctivelywith the driver, wherein light that is emitted from the first lightsource is incident on the first lens, and a central axis of lightemitted from the first lens is oblique to a rotation axis of the firstlens.

A lens according to an embodiment of the disclosure is rotatable arounda rotation axis by an external driver, and capable of emitting lighthaving an optical axis oblique to the rotation axis.

A light-emitting module according to an embodiment of the disclosureincludes a substrate, a plurality of light source units including aplurality of light sources located at the substrate and a plurality oflenses located respectively in pairs with the plurality of lightsources, a driver capable of rotating the plurality of light sourceunits in a state in which the substrate and the plurality of lightsource units are fixed, and a controller capable of controlling outputsof the plurality of light sources conjunctively with the driver, whereinlight that is emitted from the plurality of light sources is incident onthe plurality of lenses. Among the plurality of lenses, a number of thelenses capable of irradiating light while being on a trajectory in afirst irradiation region centered on a rotation axis of the plurality oflight source units is less than a number of the lenses capable ofirradiating light while being on a trajectory in a second irradiationregion centered on the rotation axis, wherein the trajectory in thesecond irradiation region is positioned outward of the trajectory in thefirst irradiation region.

According to certain embodiments of the disclosure, a light-emittingmodule that can modify a light distribution pattern and a lens that isused in such a light-emitting module can be realized.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top view showing a light-emitting module according to afirst embodiment.

FIG. 2 is a partial cross-sectional view along line II-II of FIG. 1 .

FIG. 3A is an enlarged cross-sectional view showing the first lightsource unit, the second light source unit, and a portion of thesubstrate of FIG. 2 .

FIG. 3B is a cross-sectional view showing another example of the firstlight source unit and the second light source unit.

FIG. 4A is an enlarged cross-sectional view showing the third lightsource unit, the fourth light source unit, and a portion of thesubstrate at a cross section along line IV-IV of FIG. 1 .

FIG. 4B is a cross-sectional view showing another example of the thirdlight source unit and the fourth light source unit.

FIG. 5 is a drawing showing positions at a plane orthogonal to the axisdirection of the light emitted from the light source units.

FIG. 6 is a drawing showing the positions and trajectories at the planeorthogonal to the axis direction of the light emitted from the lightsource units.

FIG. 7A is a schematic view illustrating a light distribution pattern ofa light source of a flash according to a reference example.

FIG. 7B is a schematic view illustrating a photograph imaged using thelight distribution pattern shown in FIG. 7A.

FIG. 8A is a schematic view illustrating a light distribution patternwhen applying the light-emitting module according to the firstembodiment to a light source of a flash.

FIG. 8B is a schematic view illustrating a photograph imaged using thelight distribution pattern shown in FIG. 8A.

FIG. 8C is a cross-sectional view of the light-emitting module accordingto the first embodiment mounted in a smartphone.

FIG. 9 is a top view showing a light-emitting module according to asecond embodiment.

FIG. 10 is an enlarged cross-sectional view showing the first lightsource unit, the second light source unit, and a portion of thesubstrate at a cross section along line X-X of FIG. 9 .

FIG. 11 is an enlarged cross-sectional view showing the third lightsource unit, the fourth light source unit, and a portion of thesubstrate at a cross section along line XI-XI of FIG. 9 .

FIG. 12 is a partial cross-sectional view showing a light-emittingmodule according to a third embodiment.

FIG. 13 is a cross-sectional view showing a first modification of thelens.

FIG. 14 is a cross-sectional view showing a second modification of thelens.

FIG. 15A is a schematic view for describing a modification of a methodfor controlling outputs of a plurality of light sources.

FIG. 15B is a schematic view for describing the modification of themethod for controlling the output of the plurality of light sources.

FIG. 16A is a schematic view for describing a modification of the methodfor controlling outputs of a plurality of light sources.

FIG. 16B is a schematic view for describing the modification of themethod for controlling the output of the plurality of light sources.

FIG. 17 is a top view showing a light-emitting module according to afourth embodiment.

FIG. 18 is a top view showing a light-emitting module according to afifth embodiment.

FIG. 19 is an enlarged cross-sectional view showing a plurality of lightsource units and a substrate at a cross section along line XIX-XIX ofFIG. 18 .

FIG. 20 is an enlarged cross-sectional view showing the plurality oflight source units and the substrate at a cross section along line XX-XXof FIG. 18 .

FIG. 21A is a drawing showing irradiation regions of the light emittedfrom the light source units at a plane orthogonal to the axis direction.

FIG. 21B is a schematic view for describing a method for setting theangle between the rotation axis and the central axes of the lightemitted from the light source units.

FIG. 22 is a schematic view showing a screen, a camera, and alight-emitting module according to an example.

FIG. 23A is an image captured by a camera in an example.

FIG. 23B is an image captured by a camera in an example.

FIG. 24A is an image captured by a camera in an example.

FIG. 24B is an image captured by a camera in an example.

FIG. 24C is an image captured by a camera in an example.

DETAILED DESCRIPTION

Embodiments for carrying out the invention will now be described withreference to the drawings. In the following description, portions havingthe same reference numeral in a plurality of drawings refer to the sameor equivalent portion or member. End views that show only cross sectionsmay be used as cross-sectional views.

The embodiments below illustrate light-emitting modules to give concreteform to the technical concept of the invention. However, the presentinvention is not limited to the embodiments described below. Unlessspecifically stated, the dimensions, materials, shapes, relativearrangements, and the like of the component parts described below arenot intended to limit the scope of the invention thereto, and areintended to be examples. Also, the sizes, positional relationships, andthe like of the members shown in the drawings may be exaggerated forclarity of description.

Although directions may be shown using an X-axis, a Y-axis, and a Z-axisin the drawings shown below, X-directions along the X-axis refer toprescribed directions in a plane (hereinbelow, also called anarrangement plane) in which light sources included in the light-emittingmodule according to the embodiment are arranged, Y-directions along theY-axis refer to directions orthogonal to the X-direction in thearrangement plane of the light source, and Z-directions along the Z-axisrefer to directions orthogonal to the arrangement plane of the lightsource.

Also, among the X-directions, the direction in which the arrow isoriented is notated as the +X direction, and the opposite direction ofthe +X direction is notated as the −X direction; among the Y-directions,the direction in which the arrow is oriented is notated as the +Ydirection, and the opposite direction of the +Y direction is notated asthe −Y direction; among the Z-directions, the direction in which thearrow is oriented is notated as the +Z direction, and the oppositedirection of the +Z direction is notated as the −Z direction. As anexample according to embodiments, a plurality of light sources irradiatelight toward the +Z direction side. However, such examples do not limitthe orientation when using the light-emitting module, and theorientation of the light-emitting module is arbitrary. In thespecification, “in a top view” refers to viewing an object from the +Zdirection side.

Also, when a plurality of a component exists in the specification or theclaims, the plurality may be differentiated by prefixing “first,”“second,” or the like before the component. However, the objects thatare differentiated may be different between the specification and theclaims. Therefore, even when a component recited in the claims has thesame prefix as in the specification, the object to be designated by thiscomponent does not necessarily match between the specification and theclaims.

For example, when components in the specification are differentiated byprefixing “first,” “second,” and “third,” and when the components in thespecification to which “first” and “third” are prefixed are recited inthe claims, from the perspective of ease of viewing, the components inthe claims may be differentiated by prefixing “first” and “second.” Insuch a case, the components in the claims to which “first” and “second”are prefixed refer to the components in the specification to which“first” and “third” are prefixed. The application object of this rule isnot limited to components and is reasonably and flexibly applied toother objects as well.

First Embodiment

First, a first embodiment will be described.

FIG. 1 is a top view showing a light-emitting module according to theembodiment.

FIG. 2 is a partial cross-sectional view along line II-II of FIG. 1 .

As shown in FIG. 2 , generally speaking, the light-emitting module 100includes a first light source unit 110, a driver 160, and a controller170.

The first light source unit 110 includes a first light source 111, and afirst lens 112 on which the light emitted from the first light source111 is incident.

The driver 160 is capable of rotating the first lens 112. In thespecification, “the driver being capable of rotating the first lens” mayrefer to either the driver rotating the first lens itself around an axisparallel to the Z-axis, or the driver rotating a component to which thefirst lens is mounted around an axis parallel to the Z-axis. Also, whenthe first lens rotates, other components may rotate together with thefirst lens around the axis parallel to the Z-axis. According to theembodiment as described below, the driver 160 rotates the first lightsource unit 110 that includes the first lens 112 by rotating a substrate150 to which the first lens 112 is mounted around an axis parallel tothe Z-axis.

The controller 170 controls the output of the first light source 111conjunctively with the driver 160.

In FIGS. 1 and 2 , the first lens 112 is rotated around a rotation axisC parallel to the Z-axis, and a central axis f1 of a light L1 emittedfrom the first lens 112 is oblique to the rotation axis C of the firstlens 112 (namely, the Z-axis). “The central axis of the light emittedfrom the first lens” means a straight line passing through a position a1at which the illuminance of the light emitted from the first lens 112 isa maximum in an arbitrary plane P1 orthogonal to the Z-axis and aposition a2 at which the illuminance of the light is a maximum inanother arbitrary plane P2 orthogonal to the Z-axis and separated in the+Z direction from the plane P1. Namely, the central axis of the light isthe optical axis. According to the embodiment, the first lens 112 isrotatable around the rotation axis C by the external driver 160, and iscapable of emitting the light L1 having an optical axis f1 oblique tothe rotation axis C.

Furthermore, “the central axis of the light emitted from the first lensbeing oblique to the rotation axis of the first lens” refers to thecentral axis of the light emitted from the first lens having a tilt withrespect to the rotation axis of the first lens. Also, a straight linethat is an extension of the central axis of the light emitted from thefirst lens and a straight line that is an extension of the rotation axisof the first lens may have an intersection or may be skew. This issimilar for a second lens, a third lens, and a fourth lens describedbelow as well.

According to the embodiment as shown in FIGS. 1 and 2 , thelight-emitting module 100 further includes a second light source unit120, a third light source unit 130, a fourth light source unit 140, andthe substrate 150.

The second light source unit 120 includes a second light source 121, anda second lens 122 on which the light emitted from the second lightsource 121 is incident. The third light source unit 130 includes a thirdlight source 131, and a third lens 132 on which the light emitted fromthe third light source 131 is incident. The fourth light source unit 140includes a fourth light source 141, and a fourth lens 142 on which thelight emitted from the fourth light source 141 is incident.

The first light source unit 110, the second light source unit 120, thethird light source unit 130, and the fourth light source unit 140 aremounted to the substrate 150.

The components of the light-emitting module 100 will now be elaborated.

According to the embodiment as shown in FIG. 2 , the substrate 150 is awiring substrate of which the base material is made of an insulatingmaterial such as a resin material, etc., and a plurality of wiring parts151 that are connected to the light sources 111, 121, 131, and 141 arelocated inside the substrate 150.

The surfaces of the substrate 150 include an upper surface 150 a, and alower surface 150 b positioned at the side opposite to the upper surface150 a. The upper surface 150 a and the lower surface 150 b areorthogonal to the Z-axis. Also, the upper surface 150 a is thearrangement plane of the light sources 111, 121, 131, and 141. As shownin FIG. 1 , the top-view shape of the upper surface 150 a is circular.The center of the upper surface 150 a is positioned on the rotation axisC in a top view. However, the shape of the substrate 150 in a top viewis not limited to that described above and may be polygonal such asquadrilateral, etc. Also, the center of the upper surface 150 a may bepositioned at a location other than on the rotation axis C.

FIG. 3A is an enlarged cross-sectional view of the first light sourceunit, the second light source unit, and a portion of the substrate ofFIG. 2 .

FIG. 3B is a cross-sectional view showing another example of the firstlight source unit and the second light source unit.

FIG. 4A is an enlarged cross-sectional view of the third light sourceunit, the fourth light source unit, and a portion of the substrate at across section along line IV-IV of FIG. 1 .

FIG. 4B is a cross-sectional view showing another example of the thirdlight source unit and the fourth light source unit.

As shown in FIGS. 3A and 4A, the four light sources 111, 121, 131, and141 are mounted to the upper surface 150 a. However, the number of lightsources mounted to the upper surface 150 a is not limited to this numberas long as the number is not less than one. For example, the number oflight sources mounted to the upper surface 150 a may be one to three,five, or more.

According to the embodiment, the light sources 111, 121, 131, and 141each include a light-emitting element 181, a wavelength conversionmember 182, and a light-reflective member 183.

The light-emitting element 181 is, for example, an LED (Light EmittingDiode: light-emitting diode). The light-emitting element 181 includes atleast a semiconductor stacked body and a positive and negative pair ofelectrodes 184. According to the embodiment, it is favorable to use, asthe material of the semiconductor, a nitride semiconductor that is amaterial capable of emitting light of a short wavelength that canefficiently excite the wavelength conversion substance included in thewavelength conversion member. The nitride semiconductor is mainlyrepresented by the general formula In_(x)Al_(y)Ga_(1-x-y)N (0≤x, 0≤y,and x+y<1). From the perspective of the luminous efficiency, theexcitation of the wavelength conversion substance, the color mixingrelationship of the light emission of the wavelength conversionsubstance, etc., it is favorable for the light emission peak wavelengthof the light-emitting element to be not less than 400 nm and not morethan 530 nm, more favorably not less than 420 nm and not more than 490nm, and even more favorably not less than 450 nm and not more than 475nm. Also, the material of the semiconductor can include an InAlGaAssemiconductor, an InAlGaP semiconductor, etc. The electrodes 184 of thelight-emitting element 181 are electrically connected respectively tothe wiring parts 151 of the substrate 150. According to the embodiment,the color of the light emitted from the light-emitting element 181 isblue.

The wavelength conversion member 182 is located on the light-emittingelement 181. The wavelength conversion member 182 includes a resin suchas silicone or the like as a base material, and includes a wavelengthconversion substance. The wavelength conversion substance is a memberthat absorbs at least a portion of primary light emitted by thelight-emitting element 181 and emits secondary light of a differentwavelength from the primary light. As the wavelength conversionsubstance, for example, an yttrium-aluminum-garnet-based fluorescer(e.g., Y₃(Al,Ga)₅O₁₂:Ce), a lutetium-aluminum-garnet-based fluorescer(e.g., Lu₃(Al,Ga)₅O₁₂:Ce), a terbium-aluminum-garnet-based fluorescer(e.g., Tb₃(Al,Ga)₅O₁₂:Ce), a β-sialon fluorescer (e.g.,(Si,Al)₃(O,N)₄:Eu), an α-sialon fluorescer (e.g., M_(z)(Si,Al)₁₂(O,N)₁₆(however, 0<z≤2, and M is Li, Mg, Ca, Y, and lanthanoid elements otherthan La and Ce)), a nitride-based fluorescer such as a CASN-basedfluorescer (e.g., CaAlSiN₃:Eu), a SCASN-based fluorescer (e.g.,(Sr,Ca)AlSiN₃:Eu), or the like, a fluoride-based fluorescer such as aKSF-based fluorescer (e.g., K₂SiF₆:Mn), a MGF-based fluorescer (e.g.,3.5MgO·0.5MgF₂·GeO₂:Mn), or the like, a CCA-based fluorescer (e.g.,(Ca,Sr)₁₀ (PO₄)₆Cl₂:Eu), a quantum dot of a sulfide-based fluorescer,perovskite, chalcopyrite, etc., can be used. Also, the wavelengthconversion substance can include one of these fluorescers alone, or acombination of two or more of these fluorescers. The color that isemitted by the wavelength conversion member 182 is, for example, yellow.The light sources 111, 121, 131, and 141 emit white light due to thecolor mixing of the blue of the light emitted from the light-emittingelement 181 and the yellow of the light emitted from the wavelengthconversion member 182.

To extract the light from the light-emitting element 181 toward theupper surface side (the +Z direction side), it is favorable for thelight-reflective member 183 to be a white resin in which a white pigmentsuch as titanium oxide, magnesium oxide, or the like is included in thebase material of the light-reflective member 183. Examples of the basematerial of the light-reflective member 183 include resins such assilicone, epoxy, phenol, polycarbonate, acrylic, and the like andmodified resins of such resins. The light-reflective member 183 coversat least the side surfaces of the light-emitting element 181 and thewavelength conversion member 182. The upper surface of the wavelengthconversion member 182 (the region of the wavelength conversion member182 not covered with the light-reflective member 183) is used as thelight-emitting surface (namely, the light-emitting surface) of each ofthe light sources 111, 121, 131, and 141.

The configurations of the light sources 111, 121, 131, and 141 are notlimited to those described above. For example, the wavelength conversionmember 182 of each of the light sources 111, 121, 131, and 141 mayinclude a red fluorescer that emits red light by performing wavelengthconversion of blue light, and a green fluorescer that emits green lightby performing wavelength conversion of blue light. In such a case, thelight sources 111, 121, 131, and 141 can emit white light due to thecolor mixing of the blue of the light emitted from the light-emittingelement 181 and the red and green of the light emitted from thewavelength conversion member 182. Also, the wavelength conversion member182 may be omitted from one or more light sources among the four lightsources 111, 121, 131, and 141.

Although the shapes of the light sources 111, 121, 131, and 141 in a topview are quadrilateral according to the embodiment as shown in FIG. 1 ,the shapes are not limited thereto. For example, the shapes of the lightsources 111, 121, 131, and 141 in a top view may be circular orpolygonal such as triangular or the like.

The first light source 111, the second light source 121, the third lightsource 131, and the fourth light source 141 are arranged on acircumference e centered on the rotation axis C. Specifically, in a topview, a center c1 of the first light source 111, a center c4 of thefourth light source 141, a center c2 of the second light source 121, anda center c3 of the third light source 131 are positioned clockwise inthis order on the circumference e centered on the rotation axis C. Whenthe shape of the first light source 111 in a top view is quadrilateralas in the embodiment, the center c1 is positioned at the intersection ofthe diagonal lines of the first light source 111 in a top view. This issimilar for the centers c2, c3, and c4 as well. However, the positionsof the light sources 111, 121, 131, and 141 are not limited to thosedescribed above. For example, the four light sources 111, 121, 131, and141 also may be arranged along the X-direction or the Y-direction of theupper surface 150 a of the substrate 150.

As shown in FIG. 3A, the first lens 112 is located in the +Z directionof the first light source 111, and the second lens 122 is located in the+Z direction of the second light source 121. Also, as shown in FIG. 4A,the third lens 132 is located in the +Z direction of the third lightsource 131, and the fourth lens 142 is located in the +Z direction ofthe fourth light source 141. According to the embodiment, the first lens112, the second lens 122, the third lens 132, and the fourth lens 142are formed to have a continuous body as one light-transmitting member185 by being linked at their surfaces emitting light.

According to the embodiment as shown in FIG. 3A, the first lens 112 is alens that includes a total reflection surface totally reflecting light.Specifically, the first lens 112 includes a total reflection surfacethat totally reflects light inside the first lens 112. Therefore, thelight that is emitted from the first light source 111 can be projectedby being condensed or collimated by the first lens 112. The full widthat half maximum of the light emitted from the first lens 112 is, forexample, 15 degrees. The surfaces of the first lens 112 include a firstsurface 112 a, a second surface 112 b, a third surface 112 c, and afourth surface 112 f. In FIG. 3A, the thick solid-line arrows illustratepaths of the light.

The first surface 112 a faces the first light source 111. The light thatis emitted from the first light source 111 is incident on the firstsurface 112 a. The first surface 112 a includes a first region 112 dcurved in a convex shape toward the first light source 111, and a secondregion 112 e that contacts the outer edge of the first region 112 d andextends from the outer edge of the first region 112 d toward the firstlight source 111.

As shown in FIG. 1 , the shapes of the outer perimeter of the firstregion 112 d and the outer perimeter of the second region 112 e in a topview are quadrilateral with rounded corners. The center of the firstregion 112 d is positioned on the center c1 of the first light source111 in a top view. Hereinbelow, as shown in FIG. 3A, an axis that passesthrough the center c1 parallel to the rotation axis C (namely, theZ-axis) is called a “central axis g1.” The second region 112 e isinclined away from the central axis g1 toward the −Z direction. To makethe light from the first light source 111 incident on the first lens112, it is favorable for the light-emitting surface of the first lightsource 111 to be between the two lower ends of the second region 112 ein the X-direction or the Y-direction when viewed in a cross-sectionpassing through the center c1 of the first light source 111, and it ismore favorable for the first light source 111 to be between the twolower ends of the second region 112 e in the X-direction or theY-direction as shown in FIG. 3B.

The second surface 112 b is located at the periphery of the firstsurface 112 a. The second surface 112 b is inclined to approach thecentral axis g1 toward the −Z direction. The second surface 112 breflects at least a portion of the light that enters the first lens 112through the first surface 112 a toward the interior of the first lens112. The second surface 112 b corresponds to a total reflection surface.

The third surface 112 c is positioned at the side opposite to the firstsurface 112 a. The third surface 112 c emits at least a portion of thelight that enters the first lens 112 through the first surface 112 a.The third surface 112 c is a flat surface. The flat surface (the uppersurface) of the third surface 112 c approaches the substrate 150 awayfrom the rotation axis C. Accordingly, a direction H1 perpendicular tothe third surface 112 c is inclined to become distal to the rotationaxis C toward the +Z direction at an angle θ1 a with respect to therotation axis C (namely, the central axis g1). Therefore, the greaterpart of the light propagating through the first lens 112 is refracted ina direction tilted at an angle θ1 b with respect to the rotation axis C(namely, the central axis g1) to approach the rotation axis C toward the+Z direction when emitted from the third surface 112 c. That is, thecentral axis f1 of the light emitted from the first lens 112 is tiltedat the angle θ1 b with respect to the rotation axis C (namely, thecentral axis g1) to approach the rotation axis C toward the +Zdirection.

The fourth surface 112 f is located at the periphery of the secondsurface 112 b. The fourth surface 112 f is parallel to the upper surface150 a of the substrate 150. However, the fourth surface 112 f may beoriented other than parallel to the upper surface 150 a of the substrate150. This is similar for a fourth surface 122 f of the second lens 122described below, a fourth surface 132 f of the third lens 132, and afourth surface 142 f of the fourth lens 142 as well.

According to the embodiment, the second lens 122 is a lens that includesa total reflection surface totally reflecting the light. Specifically,the second lens 122 includes a total reflection surface totallyreflecting the light inside the second lens 122. Therefore, the lightthat is emitted from the second light source 121 can be projected by thesecond lens 122 by condensing or collimating. The full width at halfmaximum of the light emitted from the second lens 122 is, for example,15 degrees. The surfaces of the second lens 122 include a first surface122 a, a second surface 122 b, a third surface 122 c, and the fourthsurface 122 f.

The first surface 122 a faces the second light source 121. The lightthat is emitted from the second light source 121 is incident on thefirst surface 122 a. The first surface 122 a includes a first region 122d curved in a convex shape toward the second light source 121, and asecond region 122 e that contacts the outer edge of the first region 122d and extends from the outer edge of the first region 122 d toward thesecond light source 121.

As shown in FIG. 1 , the shapes of the outer perimeter of the firstregion 122 d and the outer perimeter of the second region 122 e in a topview are quadrilateral with rounded corners. The center of the firstregion 122 d is positioned on the center c2 of the second light source121 in a top view. Hereinbelow, as shown in FIG. 3A, an axis that passesthrough the center c2 parallel to the rotation axis C (namely, theZ-axis) is called a “central axis g2.” The second region 122 e isinclined away from the central axis g2 toward the −Z direction. To makethe light from the second light source 121 incident on the second lens122, it is favorable for the light-emitting surface of the second lightsource 121 to be between the two lower ends of the second region 122 ein the X-direction or the Y-direction when viewed in a cross-sectionpassing through the center c2 of the second light source 121, and it ismore favorable for the second light source 121 to be between the twolower ends of the second region 122 e in the X-direction or theY-direction as shown in FIG. 3B.

The second surface 122 b is located at the periphery of the firstsurface 122 a. The second surface 122 b is inclined to approach thecentral axis g2 toward the −Z direction. The second surface 122 breflects at least a portion of the light that enters the second lens 122through the first surface 122 a toward the interior of the second lens122. The second surface 122 b corresponds to a total reflection surface.

The third surface 122 c is positioned at the side opposite to the firstsurface 122 a. The third surface 122 c emits at least a portion of thelight that enters the second lens 122 through the first surface 122 a.The third surface 122 c is a flat surface. The flat surface (the uppersurface) of the third surface 122 c approaches the substrate 150 awayfrom the rotation axis C. Accordingly, a direction H2 perpendicular tothe third surface 122 c is tilted at an angle θ2 a with respect to therotation axis C (namely, the central axis g2) to become distal to therotation axis C toward the +Z direction. Therefore, the greater part ofthe light propagating through the second lens 122 is refracted in adirection tilted at an angle θ2 b with respect to the rotation axis C(namely, the central axis g2) to approach the rotation axis C toward the+Z direction when emitted from the third surface 122 c. That is, acentral axis f2 of the light emitted from the second lens 122 is tiltedat the angle θ2 b with respect to the rotation axis C (namely, thecentral axis g2) to approach the rotation axis C toward the +Zdirection.

The fourth surface 122 f is located at the periphery of the secondsurface 122 b. The fourth surface 122 f is parallel to the upper surface150 a of the substrate 150.

According to the embodiment, the light-transmitting member 185 includesconvex portions protruding in the +Z direction due to the third surface112 c of the first lens 112 and the third surface 122 c of the secondlens 122. The fourth surface 112 f of the first lens 112 and the fourthsurface 122 f of the second lens 122 are coplanar.

According to the embodiment as shown in FIG. 4A, the third lens 132 is alens that includes a total reflection surface totally reflecting thelight. Specifically, the third lens 132 includes a total reflectionsurface that totally reflects light inside the third lens 132.Therefore, the light that is emitted from the third light source 131 canbe projected by the third lens 132 by condensing or collimating. Thefull width at half maximum of the light emitted from the third lens 132is, for example, 15 degrees. The surfaces of the third lens 132 includea first surface 132 a, a second surface 132 b, a third surface 132 c,and the fourth surface 132 f. In FIG. 4A, the thick solid-line arrowsillustrate paths of the light.

The first surface 132 a faces the third light source 131. The light thatis emitted from the third light source 131 is incident on the firstsurface 132 a. The first surface 132 a includes a first region 132 dcurved in a convex shape toward the third light source 131, and a secondregion 132 e that contacts the outer edge of the first region 132 d andextends from the outer edge of the first region 132 d toward the thirdlight source 131.

As shown in FIG. 1 , the shapes of the outer perimeter of the firstregion 132 d and the outer perimeter of the second region 132 e in a topview are quadrilateral with rounded corners. The center of the firstregion 132 d is positioned on the center c3 of the third light source131 in a top view. Hereinbelow, as shown in FIG. 4A, an axis that passesthrough the center c3 parallel to the rotation axis C (namely, theZ-axis) is called a “central axis g3.” The second region 132 e isinclined away from the central axis g3 toward the −Z direction. To makethe light from the third light source 131 incident on the third lens132, it is favorable for the light-emitting surface of the third lightsource 131 to be between the two lower ends of the second region 132 ein the X-direction or the Y-direction when viewed in a cross-sectionpassing through the center c3 of the third light source 131, and it ismore favorable for the third light source 131 to be between the twolower ends of the second region 132 e in the X-direction or theY-direction as shown in FIG. 4B.

The second surface 132 b is located at the periphery of the firstsurface 132 a. The second surface 132 b is inclined to approach thecentral axis g3 toward the −Z direction. The second surface 132 breflects at least a portion of the light that enters the third lens 132through the first surface 132 a toward the interior of the third lens132. The second surface 132 b corresponds to a total reflection surface.

The third surface 132 c is positioned at the side opposite to the firstsurface 132 a. The third surface 132 c emits at least a portion of thelight that enters the third lens 132 through the first surface 132 a.The third surface 132 c is a flat surface. The flat surface (the uppersurface) of the third surface 132 c approaches the substrate 150 awayfrom the rotation axis C. Accordingly, a direction H3 perpendicular tothe third surface 132 c is tilted at an angle θ3 a with respect to therotation axis C (namely, the central axis g3) to become distal to therotation axis C toward the +Z direction. Therefore, the greater part ofthe light propagating through the third lens 132 is refracted in adirection tilted at an angle θ3 b with respect to the rotation axis C(namely, the central axis g3) to approach the rotation axis C toward the+Z direction when emitted from the third surface 132 c. That is, acentral axis f3 of the light emitted from the third lens 132 is tiltedat the angle θ3 b with respect to the rotation axis C (namely, thecentral axis g3) to approach the rotation axis C toward the +Zdirection.

The fourth surface 132 f is located at the periphery of the secondsurface 132 b. The fourth surface 132 f is parallel to the upper surface150 a of the substrate 150. The fourth surface 132 f is coplanar and incontact with the fourth surface 112 f of the first lens 112 and thefourth surface 122 f of the second lens 122.

According to the embodiment, the fourth lens 142 is a lens that includesa total reflection surface totally reflecting light. Specifically, thefourth lens 142 includes a total reflection surface that totallyreflects light inside the fourth lens 142. Therefore, the light that isemitted from the fourth light source 141 can be projected by the fourthlens 142 by condensing or collimating. The full width at half maximum ofthe light emitted from the fourth lens 142 is, for example, 15 degrees.The surfaces of the fourth lens 142 include a first surface 142 a, asecond surface 142 b, a third surface 142 c, and the fourth surface 142f.

The first surface 142 a faces the fourth light source 141. The lightthat is emitted from the fourth light source 141 is incident on thefirst surface 142 a. The first surface 142 a includes a first region 142d curved in a convex shape toward the fourth light source 141, and asecond region 142 e that contacts the outer edge of the first region 142d and extends from the outer edge of the first region 142 d toward thefourth light source 141.

As shown in FIG. 1 , the shapes of the outer perimeter of the firstregion 142 d and the outer perimeter of the second region 142 e in a topview are quadrilateral with rounded corners. The center of the firstregion 142 d is positioned on the center c4 of the fourth light source141 in a top view. Hereinbelow, as shown in FIG. 4A, an axis that passesthrough the center c4 parallel to the rotation axis C (namely, theZ-axis) is called a “central axis g4.” The second region 142 e isinclined away from the central axis g4 toward the −Z direction. To makethe light from the fourth light source 141 incident on the fourth lens142, it is favorable for the light-emitting surface of the fourth lightsource 141 to be between the two lower ends of the second region 142 ein the X-direction or the Y-direction when viewed in a cross-sectionpassing through the center c4 of the fourth light source 141, and it ismore favorable for the fourth light source 141 to be between the twolower ends of the second region 142 e in the X-direction or theY-direction as shown in FIG. 4B.

The second surface 142 b is located at the periphery of the firstsurface 142 a. The second surface 142 b is inclined to approach thecentral axis g4 toward the −Z direction. The second surface 142 breflects at least a portion of the light that enters the fourth lens 142through the first surface 142 a toward the interior of the fourth lens142. The second surface 142 b corresponds to a total reflection surface.

The third surface 142 c is positioned at the side opposite to the firstsurface 142 a. The third surface 142 c emits at least a portion of thelight that enters the fourth lens 142 through the first surface 142 a.The third surface 142 c is a flat surface. The flat surface (the uppersurface) of the third surface 142 c approaches the substrate 150 awayfrom the rotation axis C. Accordingly, a direction H4 perpendicular tothe third surface 142 c is tilted at an angle θ4 a with respect to therotation axis C (namely, the central axis g4) to become distal to therotation axis C toward the +Z direction. Therefore, the greater part ofthe light propagating through the fourth lens 142 is refracted in adirection tilted at an angle θ4 b with respect to the rotation axis C(namely, the central axis g4) to approach the rotation axis C toward the+Z direction when emitted from the third surface 142 c. That is, acentral axis f4 of the light emitted from the fourth lens 142 is tiltedat the angle θ4 b with respect to the rotation axis C (namely, thecentral axis g4) to approach the rotation axis C toward the +Zdirection.

The fourth surface 142 f is located at the periphery of the secondsurface 142 b. The fourth surface 142 f is parallel to the upper surface150 a of the substrate 150. The fourth surface 142 f is coplanar and incontact with the fourth surface 112 f of the first lens 112 and thefourth surface 122 f of the second lens 122.

According to the embodiment, the light-transmitting member 185 includesconvex portions protruding in the +Z direction due to the third surface132 c of the third lens 132 and the third surface 142 c of the fourthlens 142. As shown in FIG. 1 , the third surface 112 c of the first lens112 contacts the third surface 132 c of the third lens 132 and the thirdsurface 142 c of the fourth lens 142. The third surface 122 c of thesecond lens 122 contacts the third surface 132 c of the third lens 132and the third surface 142 c of the fourth lens 142.

According to the embodiment as shown in FIGS. 3A and 4A, the angle θ1 a,the angle θ2 a, the angle θ3 a, and the angle θ4 a are different fromeach other, i.e., angle θ3 a<angle θ2 a<angle θ4 a<angle θ1 a.Accordingly, angle θ3 b<angle θ2 b<angle θ4 b<angle θ1 b. The magnituderelationship of the angle θ1 a, the angle θ2 a, the angle θ3 a, and theangle θ4 a is not limited to that described above because the tiltangles of the third surface 112 c of the first lens 112, the thirdsurface 122 c of the second lens 122, the third surface 132 c of thethird lens 132, and the third surface 142 c of the fourth lens 142 withrespect to the rotation axis C (or the Z-axis) can be adjusted asappropriate.

While being flat surfaces according to the embodiment, the third surface112 c of the first lens 112, the third surface 122 c of the second lens122, the third surface 132 c of the third lens 132, and the thirdsurface 142 c of the fourth lens 142 are not limited to flat surfaces aslong as the central axes f1, f2, f3, and f4 of the light emitted fromthe lenses are oblique to the rotation axis C.

Also, the center c1 of the first light source 111 may be shifted fromthe center of the first region 112 d in a top view. In particular, whenthe distance between the rotation axis C and the center c1 of the firstlight source 111 is greater than the distance between the rotation axisC and the center of the first region 112 d, the first light source 111is separated from the second lens 122 compared to when the center c1 ofthe first light source 111 is positioned on the center of the firstregion 112 d in a top view. As a result, the light that is emitted fromthe first light source 111 can be prevented from traveling toward thethird surface 122 c of the second lens 122 after entering the first lens112. There is a possibility that a portion of the light emitted from thefirst light source 111 and entering the first lens 112 may be refractedin a direction other than the direction tilted at the angle θ2 b withrespect to the rotation axis C (namely, the Z-axis) when a portion ofthe light propagates through the second lens 122 and is emitted from thethird surface 122 c of the second lens 122. In other words, there is apossibility that light (stray light) also may be emitted from the thirdsurface 122 c toward a direction other than the expected light towardthe direction tilted at the angle θ2 b with respect to the rotation axisC. As described above, by separating the first light source 111 from thesecond lens 122, the light that is emitted from the first light source111 can be prevented from traveling toward the third surface 122 c ofthe second lens 122 after entering the first lens 112. As a result, theoccurrence of such stray light can be suppressed. The positionalrelationship between the second lens 122 and the second light source121, the positional relationship between the third lens 132 and thethird light source 131, and the positional relationship between thefourth lens 142 and the fourth light source 141 also may have similarconfigurations.

According to the embodiment, the rotation axis C, the Z-axis, and thecentral axes g1, g2, g3, and g4 are parallel to each other. Therefore,according to the first embodiment, when a straight line that is anextension of the central axis f1 of the light emitted from the firstlens 112 and a straight line that is an extension of the rotation axis Cof the first lens 112 have an intersection or are skew, “the anglebetween the rotation axis C and the central axis f1 of the light emittedfrom the first lens 112” is the same as “the angle between the Z-axisand the central axis f1 of the light emitted from the first lens 112” or“the angle between the central axis f1 of the light emitted from thefirst lens 112 and the central axis g1 passing through the center c1 ofthe first light source 111.” This is similar for the second lens 122,the third lens 132, and the fourth lens 142 as well.

As shown in FIGS. 3A and 4A, a support part 187 that extends toward thesubstrate 150 is located at the outer perimeter portion of thelight-transmitting member 185. The support part 187 is fixed to theupper surface 150 a of the substrate 150. The support part 187 holds thelenses 112, 122, 132, and 142 in a state of being separated from thelight sources 111, 121, 131, and 141. According to the embodiment asshown in FIG. 1 , the support part 187 has a tubular shape surroundingthe periphery of the first lens 112, the second lens 122, the third lens132, and the fourth lens 142. The support part 187 is not limited to atubular shape and may be a plurality of columnar-shaped support partsarranged at the outer perimeter of the light-transmitting member 185.Also, the support part may include a member other than thelight-transmitting member 185. In such a case, the support part is notnecessarily transmissive.

Also, the light-transmitting member 185 is not necessarily formed of thefour lenses 112, 122, 132, and 142 formed to have a continuous body. Forexample, the lenses 112, 122, 132, and 142 that are made of differentmaterials or have different refractive indexes may be bonded to form acontinuous body by an adhesive, etc. Also, the lenses 112, 122, 132, and142 that are made of different materials or have different refractiveindexes may be individually mounted to the upper surface 150 a of thesubstrate 150 without being bonded to each other.

According to the embodiment as shown in FIG. 2 , the driver 160 rotatesthe first light source unit 110, the second light source unit 120, thethird light source unit 130, and the fourth light source unit 140 byrotating the substrate 150 around an axis parallel to the Z-axis.

According to the embodiment, the driver 160 includes a motor 161, and ashaft 162 that is linked to the substrate 150 and moves with the motor161. The shaft 162 rotates when the motor 161 drives. In response to therotation of the shaft 162, the substrate 150 rotates around the rotationaxis C, which is parallel to the Z-axis, as a central axis, and thelight-transmitting member 185 (the lenses 112, 122, 132, and 142) thatis fixed to the substrate 150 rotates.

A rotary connector 190 that includes a ring unit 191 and a brush unit192 is located at the shaft 162. According to the embodiment, the rotaryconnector 190 is a slip ring. The rotary connector 190 electricallyconnects the controller 170 and the plurality of wiring parts 151embedded in the rotating substrate 150.

The ring unit 191 includes a tubular body 191 a that is linked to theshaft 162 and has the shaft 162 located in the interior of the tubularbody 191 a, and a plurality of rings 191 b that are located at the outerperimeter of the tubular body 191 a and are conductive. The ring unit191 rotates together with the shaft 162. The plurality of rings 191 band the plurality of wiring parts 151 embedded in the substrate 150 areelectrically connected one-to-one via the interior of the shaft 162 andthe interior of the tubular body 191 a.

The brush unit 192 includes a plurality of brushes 192 a that areconductive and respectively contact the plurality of rings 191 b, and aholder 192 b that holds the plurality of brushes 192 a. The plurality ofbrushes 192 a are individually electrically connected to the controller170. In FIG. 2 , the connectional relationship between the controller170 and the rotary connector 190 is simply shown by one line. Thecontroller 170 and the brush unit 192 do not rotate. For example, whenthe light-emitting module 100 is used as the light source of the flashof a smartphone, the controller 170 and the brush unit 192 are fixedwith respect to the housing of the smartphone, etc. Therefore, when themotor 161 is driven, the brush unit 192 can transmit an electricalsignal to the ring unit 191 without rotating. However, thelight-emitting module 100 may be used other than as the light source ofa flash of a smartphone.

The configuration of the rotary connector 190 is not limited to theconfiguration described above. For example, the rotary connector 190 maybe a rotary connector that uses a liquid metal, etc.

The controller 170 includes, for example, a CPU (Central ProcessingUnit), memory, etc. The controller 170 is electrically connected to themotor 161 of the driver 160. The controller 170 rotates the substrate150 around the rotation axis C by controlling the motor 161. Althoughnot particularly limited, the rotational speed of the substrate 150 is,for example, not less than 60 rpm and not more than 24000 rpm. Therotational speed of the substrate 150 is, for example, 14000 rpm.However, the controller 170 may be configured to be able to adjust thenumber of rotations of the motor 161.

The controller 170 individually controls the outputs of the four lightsources 111, 121, 131, and 141. “Control the output” includes switchingthe light source on, switching the light source off, and adjusting theluminance of the light emitted from the light source when the lightsource is lit. Specifically, the controller 170 individually controlsthe outputs of the light sources 111, 121, 131, and 141 by individuallyadjusting the current amounts supply to the light sources 111, 121, 131,and 141 via the rotary connector 190.

The controller 170 controls the output of the first light source 111according to the position of the circumferential trajectory of thecentral axis f1 of the light emitted from the first lens 112 when thesubstrate 150 is rotated around the rotation axis C. Also, thecontroller 170 controls the output of the second light source 121according to the position of the circumferential trajectory of thecentral axis f2 of the light emitted from the second lens 122 when thesubstrate 150 is rotated around the rotation axis C. Also, thecontroller 170 controls the output of the third light source 131according to the position of the circumferential trajectory of thecentral axis f3 of the light emitted from the third lens 132 when thesubstrate 150 is rotated around the rotation axis C. Also, thecontroller 170 controls the output of the fourth light source 141according to the position of the circumferential trajectory of thecentral axis f4 of the light emitted from the fourth lens 142 when thesubstrate 150 is rotated around the rotation axis C.

For example, the controller 170 may estimate the positions on thetrajectories of the central axes f1, f2, f3, and f4 of the light basedon the positions of the lenses 112, 122, 132, and 142 prior to rotation,the rotational speed and/or number of rotations of the motor 161, etc.Also, the controller 170 may estimate the positions on the trajectoriesof the central axes f1, f2, f3, and f4 of the light during rotation byusing the detection result of a rotation angle detection sensor such asa rotary encoder, etc. Specifically, the rotation angle detection sensoruses a state in which the substrate 150 is not rotating or the like as areference state and detects the rotation amount (the rotation angle) ofthe substrate 150 from the reference state. Then, the positions on thetrajectories of the central axes f1, f2, f3, and f4 of the light duringrotation can be estimated based on the rotation angle of the substrate150 from the reference state.

Operations of the light-emitting module 100 according to the embodimentwill now be described.

FIG. 5 is a drawing showing positions at a plane orthogonal to theZ-axis of the light emitted from the light source units.

FIG. 6 is a drawing showing the positions and trajectories at the planeorthogonal to the Z-axis of the light emitted from the light sourceunits.

When the light sources 111, 121, 131, and 141 are lit in a state inwhich the substrate 150 is not rotating as shown in FIG. 5 , the centralaxes f1, f2, f3, and f4 of the light emitted from the light sources 111,121, 131, and 141 are tilted to become distal to the rotation axis Caway from the light-emitting module 100 in the +Z direction. Therefore,the light can be irradiated in a wide area while keeping thelight-emitting module 100 compact.

According to the embodiment, angle θ3 b<angle θ2 b<angle θ4 b<angle θ1b. Accordingly, as shown in FIG. 6 , the trajectory of the central axisf3 of light L3 emitted from the third lens 132 is at a positionseparated from the rotation axis C in one plane P3 orthogonal to theZ-axis. The trajectory of the central axis f2 of light L2 emitted fromthe second lens 122 is at a position separated from the rotation axis Cmore than the position of the trajectory of the central axis f3 in theplane P3. The trajectory of the central axis f4 of light L4 emitted fromthe fourth lens 142 is at a position separated from the rotation axis Cmore than the position of the trajectory of the central axis f2 in theplane P3. The trajectory of the central axis f1 of the light L1 emittedfrom the first lens 112 is at a position separated from the rotationaxis C more than the position of the trajectory of the central axis f4in the plane P3.

When the substrate 150 rotates once around the rotation axis C in thestate in which the four light sources 111, 121, 131, and 141 are lit,the light source units 110, 120, 130, and 140 also rotate once aroundthe rotation axis C. At this time, the central axis f3 of the thirdlight source unit 130 moves in the plane P3 on a circumferentialtrajectory e3 centered on the rotation axis C. The central axis f2 ofthe second light source unit 120 moves in the plane P3 on acircumferential trajectory e2 that is centered on the rotation axis Cand has a larger radius than the trajectory e3. The central axis f4 ofthe fourth light source unit 140 moves in the plane P3 on acircumferential trajectory e4 that is centered on the rotation axis Cand has a larger radius than the trajectory e2. The central axis f1 ofthe first light source unit 110 moves in the plane P3 on acircumferential trajectory e1 that is centered on the rotation axis Cand has a larger radius than the trajectory e4.

At this time, the controller 170 can realize various light distributionpatterns by controlling the outputs of the light sources 111, 121, 131,and 141 according to the positions of the central axes f1, f2, f3, andf4 in the rotational direction.

Hereinbelow, the region on which the light L1 emitted from the firstlight source unit 110 is irradiated when the substrate 150 is rotatedonce around the rotation axis C in the state in which the first lightsource 111 is lit is called a “first irradiation region h1.” Also, theregion on which the light L2 emitted from the second light source unit120 is irradiated when the substrate 150 is rotated once around therotation axis C in the state in which the second light source 121 is litis called a “second irradiation region h2.” Also, the region on whichthe light L3 emitted from the third light source unit 130 is irradiatedwhen the substrate 150 is rotated once around the rotation axis C in thestate in which the third light source 131 is lit is called a “thirdirradiation region h3.” The region on which the light L4 emitted fromthe fourth light source unit 140 is irradiated when the substrate 150 isrotated once around the rotation axis C in the state in which the fourthlight source 141 is lit is called a “fourth irradiation region h4.”

Although FIG. 6 shows a one-to-one relationship for the regions (i.e.,the first irradiation region h1, the second irradiation region h2, thethird irradiation region h3, and the fourth irradiation region h4,generally referred to as the “irradiation regions” below) on which thelight from the light source units 110, 120, 130, and 140 is irradiated,the light that is emitted from the light source units is not actuallylimited to illuminating only the corresponding irradiation region. Theirradiation region that corresponds to each light source unit is theregion that is the irradiation target of the light source unit.Accordingly, actually, the light that is emitted from one light sourceunit also may illuminate at least a portion of an adjacent irradiationregion. That is, although FIG. 6 shows an example in which the adjacentirradiation regions do not overlap, the adjacent irradiation regions maypartially overlap.

For example, according to the embodiment, the first irradiation regionh1, the second irradiation region h2, and the fourth irradiation regionh4 are ring-shaped. In contrast, the third irradiation region h3 iscircular. Thus, the irradiation region changes from ring-shaped towardcircular as the angle between the rotation axis and the central axis ofthe light decreases.

According to the embodiment, all of the central axes f1, f2, f3, and f4of the lights L1, L2, L3, and L4 emitted from the lenses 112, 122, 132,and 142 are oblique to the rotation axis C. However, it is sufficientfor the central axis of the light emitted from at least one lens to beoblique to the rotation axis C. For example, the light-emitting modulemay include a lens emitting light having a central axis parallel to therotation axis C. The trajectory of the central axis in the plane P3 ofthe light emitted from such a lens is positioned inward of thetrajectory of the light having central axes oblique to the rotation axisC. Also, although the trajectory of the central axis of the lightemitted from such a lens is a circumferential trajectory, theirradiation region of the light emitted from such a lens is circular inthe plane P3 similarly to the third irradiation region h3 shown in FIG.6 .

An application example of the light-emitting module 100 will now bedescribed. The light-emitting module 100 is applicable to the lightsource of a flash of a smartphone camera.

FIG. 7A is a schematic view illustrating a light distribution pattern ofa light source of a flash according to a reference example.

FIG. 7B is a schematic view illustrating a photograph imaged using thelight distribution pattern shown in FIG. 7A.

FIG. 8A is a schematic view illustrating a light distribution patternwhen applying the light-emitting module 100 according to the embodimentto the light source of the flash.

FIG. 8B is a schematic view illustrating a photograph imaged using thelight distribution pattern shown in FIG. 8A.

As shown in FIG. 7A, for a light source of the flash in which the lightdistribution pattern is always constant (a light distribution patternA11), for example, the illuminance is highest at the central portion ofthe light distribution pattern. Therefore, as shown in FIG. 7B, in aphotograph A12 imaged using the light distribution pattern A11, animaging subject S1 proximate to the light source of the flash becomesbright, and an imaging subject S2 distant to the light source of theflash becomes dark. As a result, in the photograph A12, the imagingsubject S1 that is proximate to the light source of the flash may bewhited out, and the imaging subject S2 that is distant to the lightsource of the flash may be blacked out. Thus, for a light source of aflash in which the light distribution pattern is always constant, aphenomenon of lost gradation may occur.

In contrast, for a light source of a flash to which the light-emittingmodule 100 according to the embodiment is applied, the lightdistribution pattern can be adjusted according to the distances betweenthe light-emitting module 100 and the imaging subjects S1 and S2.Specifically, as shown in FIG. 8A, the light-emitting module 100 emits alight distribution pattern A21 in which the illuminance of the imagingsubject S1 is less than the illuminance of the imaging subject S2.Specifically, in the light distribution pattern A21, the illuminances inthe entire third irradiation region h3, the lower region of the secondirradiation region h2, the lower region of the fourth irradiation regionh4, and the lower region of the first irradiation region h1 are lessthan the illuminances in the other regions of the light distributionpattern A21.

Therefore, in a photograph A22 imaged using the light distributionpattern A21 as shown in FIG. 8B, the excessive brightness of the imagingsubject Si proximate to the light source of the flash is suppressed, andthe excessive darkness of the imaging subject S2 distant to the lightsource of the flash is suppressed. As a result, the occurrence ofwhite-out and/or black-out in the photograph A22 can be suppressed.

FIG. 8C is a cross-sectional view of the light-emitting module accordingto the embodiment mounted in a smartphone.

In the light-emitting module 100 according to the embodiment, atransmissive cover member 910 may be located above (in the +Z direction)of the lenses 112, 122, 132, and 142. For example, when thelight-emitting module according to the embodiment is mounted in a devicesuch as a smartphone, etc., it is favorable for the transmissive covermember 910 to be located above (in the +Z direction) of the lenses 112,122, 132, and 142 from the perspective of preventing the user of thedevice from contacting the rotating lenses 112, 122, 132, and 142. Forexample, such a cover member 910 is mounted to a housing 920 of a devicesuch as a smartphone, etc. For example, the cover member 910 is made ofa light-transmitting material such as glass, a polycarbonate resin, etc.For example, the housing 920 is made of a metal or a resin (e.g., apolycarbonate resin) that includes a light-diffusing material such astitanium oxide or the like or a light-absorbing material such as a blackpigment or the like.

According to the embodiment, the light that is emitted from the lenses112, 122, 132, and 142 travels in directions toward the rotation axis C.Therefore, the light that is emitted from the lenses 112, 122, 132, and142 easily is incident on the cover member 910. Shielding of the lightemitted from the lenses 112, 122, 132, and 142 by the housing 920, etc.,can be suppressed thereby.

Effects of the embodiment will now be described.

The light-emitting module 100 according to the embodiment includes thefirst light source unit 110 that includes the first light source 111 andthe first lens 112 on which the light emitted from the first lightsource 111 is incident, the driver 160 that is capable of rotating thefirst lens 112, and the controller 170 that controls the output of thefirst light source 111 conjunctively with the driver 160. The centralaxis f1 of the light L1 emitted from the first lens 112 is oblique tothe rotation axis C of the first lens 112. Therefore, the light can beirradiated on a wide region by one light source unit 110. Furthermore,the controller 170 can modify the light distribution pattern bycontrolling the output of the first light source 111 conjunctively withthe driver 160. Accordingly, a light-emitting module can be realized inwhich the light distribution pattern can be modified. Also, the lightdistribution pattern can be modified even when the number of lightsources is low.

Also, the driver 160 is capable of rotating the first light source unit110 around the rotation axis C. Thus, by rotating the first light source111 together with the first lens 112, the light-emitting module 100 canhave a simple structure.

Also, the light-emitting module 100 includes the second light sourceunit 120 that includes the second light source 121 and the second lens122 on which the light emitted from the second light source 121 isincident, and the substrate 150 to which the first light source unit 110and the second light source unit 120 are mounted. By rotating thesubstrate 150 around the rotation axis C, the driver 160 is capable ofrotating the second light source unit 120 around the rotation axis Ctogether with the first light source unit 110. The controller 170controls the output of the second light source 121 conjunctively withthe driver 160. Also, the central axis f2 of the light L2 emitted fromthe second lens 122 is oblique to the rotation axis C. The angle (theangle θ2 b) between the rotation axis C (namely, the central axis g2)and the central axis f2 of the light L2 emitted from the second lens 122is different from the angle (the angle θ1 b) between the rotation axis C(namely, the central axis g1) and the central axis f1 of the light L1emitted from the first lens 112. Therefore, various light distributionpatterns can be realized by the two light source units 110 and 120.

Also, the first light source unit 110 and the second light source unit120 are on a circumference centered on the rotation axis C on thesubstrate 150. Therefore, the light-emitting module 100 can be compact.

Also, the controller 170 controls the output of the first light source111 according to the position of the circumferential trajectory of thecentral axis f1 of the light emitted from the first lens 112. Therefore,various light distribution patterns can be realized.

Also, the first lens 112 is a lens that includes a total reflectionsurface totally reflecting light. The first lens 112 includes the firstsurface 112 a on which the light emitted from the first light source 111is incident, the second surface 112 b that is located at the peripheryof the first surface 112 a and reflects at least a portion of the lightthat enters the first lens 112 through the first surface 112 a, and thethird surface 112 c that is positioned at the side opposite to the firstsurface 112 a and emits the light that enters through the first surface112 a. The first lens 112 can project the light emitted from the firstlight source 111 by condensing or collimating.

Also, the direction H1 that is orthogonal to the third surface 112 c ofthe first lens 112 is oblique to the Z-axis. In other words, the centralaxis f1 of the light L1 emitted from the first lens 112 can be obliqueto the rotation axis C by using a simple configuration in which thethird surface 112 c of the first lens 112 is oblique to the rotationaxis C.

An example is described in the first embodiment in which the anglesbetween the rotation axis C and the central axes of the light emittedfrom the first lens 112, the second lens 122, the third lens 132, andthe fourth lens 142 are different from each other. However, for example,the angle between the rotation axis C and the central axis f1 of thelight emitted from the first lens 112 and the angle between the rotationaxis C and the central axis f2 of the light emitted from the second lens122 may be the same. In such a case, the first irradiation region h1 andthe second irradiation region h2 overlap. Therefore, the light-emittingmodule 100 can emit a toned light by setting the light emitted from thefirst light source 111 to be white light and by setting the lightemitted from the second light source 121 to be white light having adifferent color temperature from the light emitted from the first lightsource 111. Furthermore, in such a case, the angle between the rotationaxis C and the central axis f3 of the light emitted from the third lens132 may be different from the angle between the rotation axis C and thecentral axis f1 of the light emitted from the first lens 112 and thesame as the angle between the rotation axis C and the central axis f4 ofthe light emitted from the fourth lens 142. In such a case, the thirdirradiation region h3 and the fourth irradiation region h4 overlap.Therefore, by setting the color of the light emitted from the thirdlight source 131 to be the same as the color of the light emitted fromthe first light source 111 and by setting the color of the light emittedfrom the fourth light source 141 to be the same as the color of thelight emitted from the second light source 121, various lightdistribution patterns can be realized while emitting toned light fromthe light-emitting module 100.

Second Embodiment

A second embodiment will now be described.

FIG. 9 is a top view showing a light-emitting module according to theembodiment.

FIG. 10 is an enlarged cross-sectional view showing the first lightsource unit, the second light source unit, and a portion of thesubstrate at a cross section along line X-X of FIG. 9 .

FIG. 11 is an enlarged cross-sectional view showing the third lightsource unit, the fourth light source unit, and a portion of thesubstrate at a cross section along line XI-XI of FIG. 9 .

Configurations of a first lens 212, a second lens 222, a third lens 232,and a fourth lens 242 of the light-emitting module 200 according to theembodiment are different from those of the light-emitting module 100according to the first embodiment.

As a general rule in the following description, the differences betweenthe first embodiment are mainly described. Other than the itemsdescribed below, the embodiment is similar to the first embodiment. Thisis similar for the embodiments and modifications below as well.

As shown in FIG. 9 , the light-emitting module 200 includes a firstlight source unit 210, a second light source unit 220, a third lightsource unit 230, and a fourth light source unit 240. The first lightsource unit 210 includes the first light source 111, and the first lens212 on which the light emitted from the first light source 111 isincident. The second light source unit 220 includes the second lightsource 121, and the second lens 222 on which the light emitted from thesecond light source 121 is incident. The third light source unit 230includes the third light source 131, and the third lens 232 on which thelight emitted from the third light source 131 is incident. The fourthlight source unit 240 includes the fourth light source 141, and thefourth lens 242 on which the light emitted from the fourth light source141 is incident.

According to the embodiment, the four lenses 212, 222, 232, and 242 areformed to have a continuous body as one light-transmitting member 385 bybeing linked at the surface emitting light.

As shown in FIG. 10 , the first lens 212 is located in the +Z directionof the first light source 111. According to the embodiment, the firstlens 212 is a lens that includes a total reflection surface totallyreflecting light. Specifically, the first lens 212 includes a totalreflection surface that totally reflects light inside the first lens212. The surfaces of the first lens 212 include a first surface 212 a, asecond surface 212 b, a third surface 212 c, and a fourth surface 212 f.Paths of the light are illustrated by solid-line arrows in FIG. 10 .

The configuration of the first surface 212 a is similar to theconfiguration of the first surface 112 a of the first lens 112 accordingto the first embodiment; the configuration of the second surface 212 bis similar to the configuration of the second surface 112 b of the firstlens 112 according to the first embodiment; the configuration of thefourth surface 212 f is similar to the configuration of the fourthsurface 112 f of the first lens 112 according to the first embodiment,and descriptions thereof are therefore omitted.

The third surface 212 c is positioned at the side opposite to the firstsurface 212 a. The third surface 212 c emits at least a portion of thelight that enters the first lens 212 through the first surface 212 a.The third surface 212 c is a flat surface. The flat surface (the uppersurface) of the third surface 212 c is inclined to become distal to thesubstrate 150 away from the rotation axis C. Accordingly, a directionH21 perpendicular to the third surface 212 c is tilted at an angle θ21 awith respect to the rotation axis C to approach the rotation axis Ctoward the +Z direction. Therefore, the greater part of the lightpropagating through the first lens 212 is refracted in a directiontilted at an angle θ21 b with respect to the rotation axis C to becomedistal to the rotation axis C toward the +Z direction when emitted fromthe third surface 212 c. That is, the central axis f21 of the lightemitted from the first lens 212 is tilted at the angle θ21 b withrespect to the rotation axis C to become distal to the rotation axis Ctoward the +Z direction.

The second lens 222 is located in the +Z direction of the second lightsource 121. According to the embodiment, the second lens 222 is a lensthat includes a total reflection surface totally reflecting light.Specifically, the second lens 222 includes a total reflection surfacethat totally reflects light inside the second lens 222. The surfaces ofthe second lens 222 include a first surface 222 a, a second surface 222b, a third surface 222 c, and a fourth surface 222 f.

The configuration of the first surface 222 a is similar to theconfiguration of the first surface 122 a of the second lens 122according to the first embodiment; the configuration of the secondsurface 222 b is similar to the configuration of the second surface 122b of the second lens 122 according to the first embodiment; the fourthsurface 222 f is similar to the configuration of the fourth surface 122f of the second lens 122 according to the first embodiment, anddescriptions thereof are therefore omitted.

The third surface 222 c is positioned at the side opposite to the firstsurface 222 a. The third surface 222 c emits at least a portion of thelight that enters the second lens 222 through the first surface 222 a.The third surface 222 c is a flat surface. The flat surface (the uppersurface) of the third surface 222 c is inclined to become distal to thesubstrate 150 away from the rotation axis C. Accordingly, a directionH22 perpendicular to the third surface 222 c is tilted at an angle θ22 awith respect to the rotation axis C to approach the rotation axis Ctoward the +Z direction. Therefore, the greater part of the lightpropagating through the second lens 222 is refracted in a directiontilted at an angle θ22 b with respect to the rotation axis C to becomedistal to the rotation axis C toward the +Z direction when emitted fromthe third surface 222 c. That is, a central axis f22 of the lightemitted from the second lens 222 is tilted at the angle θ22 b withrespect to the rotation axis C to become distal to the rotation axis Ctoward the +Z direction.

According to the embodiment, a recess that is concave toward the −Zdirection is formed in the light-transmitting member 385 by the thirdsurface 212 c of the first lens 212 and the third surface 222 c of thesecond lens 222.

As shown in FIG. 11 , the third lens 232 is located in the +Z directionof the third light source 131. According to the embodiment, the thirdlens 232 is a lens that includes a total reflection surface totallyreflecting light. Specifically, the third lens 232 includes a totalreflection surface totally reflecting light inside the third lens 232.The surfaces of the third lens 232 include a first surface 232 a, asecond surface 232 b, a third surface 232 c, and a fourth surface 232 f.Paths of the light are illustrated by solid-line arrows in FIG. 11 .

The configuration of the first surface 232 a is similar to theconfiguration of the first surface 132 a of the third lens 132 accordingto the first embodiment; the configuration of the second surface 232 bis similar to the configuration of the second surface 132 b of the thirdlens 132 according to the first embodiment; the configuration of thefourth surface 232 f is similar to the configuration of the fourthsurface 132 f of the third lens 132 according to the first embodiment,and descriptions thereof are therefore omitted.

The third surface 232 c is positioned at the side opposite to the firstsurface 232 a. The third surface 232 c emits at least a portion of thelight that enters the third lens 232 through the first surface 232 a.The third surface 232 c is a flat surface. The flat surface (the uppersurface) of the third surface 232 c is inclined to become distal to thesubstrate 150 away from the rotation axis C. Accordingly, a directionH23 perpendicular to the third surface 232 c is tilted at an angle θ23 awith respect to the rotation axis C to approach the rotation axis Ctoward the +Z direction. Therefore, the greater part of the lightpropagating through the third lens 232 is refracted in a directiontilted at an angle θ23 b with respect to the rotation axis C to becomedistal to the rotation axis C toward the +Z direction when emitted fromthe third surface 232 c. That is, a central axis f23 of the lightemitted from the third lens 232 is tilted at the angle θ23 b withrespect to the rotation axis C to become distal to the rotation axis Ctoward the +Z direction.

The fourth lens 242 is located in the +Z direction of the fourth lightsource 141. According to the embodiment, the fourth lens 242 is a lensthat includes a total reflection surface totally reflecting light.Specifically, the fourth lens 242 includes a total reflection surfacetotally reflecting light inside the fourth lens 242. The surfaces of thefourth lens 242 include a first surface 242 a, a second surface 242 b, athird surface 242 c, and a fourth surface 242 f.

The configuration of the first surface 242 a is similar to theconfiguration of the first surface 142 a of the fourth lens 142according to the first embodiment; the configuration of the secondsurface 242 b is similar to the configuration of the second surface 142b of the fourth lens 142 according to the first embodiment; theconfiguration of the fourth surface 242 f is similar to the fourthsurface 142 f of the fourth lens 142 according to the first embodiment,and descriptions thereof are therefore omitted.

The third surface 242 c is positioned at the side opposite to the firstsurface 242 a. The third surface 242 c emits at least a portion of thelight that enters the fourth lens 242 through the first surface 242 a.The third surface 242 c is a flat surface. The flat surface (the uppersurface) of the third surface 242 c is inclined to become distal to thesubstrate 150 away from the rotation axis C. Accordingly, a directionH24 perpendicular to the third surface 242 c is tilted at an angle θ24 awith respect to the rotation axis C to approach the rotation axis Ctoward the +Z direction. Therefore, the greater part of the lightpropagating through the fourth lens 242 is refracted in a directiontilted at an angle θ24 b with respect to the rotation axis C to becomedistal to the rotation axis C toward the +Z direction when emitted fromthe third surface 242 c. That is, a central axis f24 of the lightemitted from the fourth lens 242 is tilted at the angle θ24 b withrespect to the rotation axis C to become distal to the rotation axis Ctoward the +Z direction.

According to the embodiment, a recess that is concave toward the −Zdirection is formed in the light-transmitting member 385 by the thirdsurface 232 c of the third lens 232 and the third surface 242 c of thefourth lens 242.

According to the embodiment, the angle θ21 a, the angle θ22 a, the angleθ23 a, and the angle θ24 a are different from each other, i.e., angleθ23 a<angle θ22 a<angle θ24 a<angle θ21 a. Accordingly, angle θ23b<angle θ22 b<angle θ24 b<angle θ21 b. The magnitude relationship of theangle θ21 a, the angle θ22 a, the angle θ23 a, and the angle θ24 a isnot limited to that described above because the tilt angles with respectto the rotation axis C (or the Z-axis) of the third surface 212 c of thefirst lens 212, the third surface 222 c of the second lens 222, thethird surface 232 c of the third lens 232, and the third surface 242 cof the fourth lens 242 can be adjusted as appropriate.

As described above, the third surfaces 212 c, 222 c, 232 c, and 242 calso may be tilted to become distal to the substrate 150 away from therotation axis C.

In the light-emitting module 200 according to the embodiment, a recessthat is concave toward the substrate 150 is formed by the third surface212 c of the first lens 212 and the third surface 222 c of the secondlens 222. Therefore, a thickness T2 of the portion of thelight-transmitting member 385 between the first lens 212 and the secondlens 222 can be thin compared to a thickness T1 of the portion of thelight-transmitting member 185 between the first lens 112 and the secondlens 122 according to the first embodiment (see FIG. 3A). The occurrenceof stray light such as that entering the second lens 222 from the firstlens 212 or stray light such as that entering the first lens 212 fromthe second lens 222 can be suppressed thereby. In other words, in thelight-transmitting member 385, the occurrence of stray light enteringthe different lenses can be suppressed by the link portion of the firstlens 212, the second lens 222, the third lens 232, and the fourth lens242.

Third Embodiment

FIG. 12 is a partial cross-sectional view showing a light-emittingmodule according to the embodiment.

The light-emitting module 300 according to the embodiment differs fromthe light-emitting module 100 according to the first embodiment in thatone light source unit 310 is provided, and a lens 312 of the lightsource unit 310 rotates with respect to a light source 311.

The light-emitting module 300 includes a substrate 350, the light sourceunit 310, a driver 360, and a controller 370. The light source unit 310includes the light source 311 and the lens 312.

According to the embodiment, the substrate 350 is a wiring substrate inwhich a plurality of wiring parts connected to the light source 311 arelocated in a base material made of an insulating material such as aresin material, etc. The light source 311 is mounted on the substrate350. The upper surface and lower surface of the substrate 350 areorthogonal to the Z-axis.

The configuration of the light source 311 is similar to that of thefirst light source 111 according to the first embodiment, and adescription is therefore omitted. The lens 312 is located in the +Zdirection of the light source 311.

According to the embodiment, the lens 312 is a lens that includes atotal reflection surface totally reflecting light. Specifically, thelens 312 includes a total reflection surface that totally reflects lightinside the lens 312. The lens 312 is held by a holding part 313 torotate around the rotation axis C. When, for example, the light-emittingmodule 300 is used as the light source of a flash of a smartphone, thesubstrate 350 and the holding part 313 are fixed to the housing of thesmartphone, etc. However, the light-emitting module 300 may be usedother than as a light source of a flash of a smartphone.

The surfaces of the lens 312 include a first surface 312 a, a secondsurface 312 b, a third surface 312 c, a fourth surface 312 g, and afifth surface 312 h. Paths of the light are illustrated by thicksolid-line arrows in FIG. 12 .

The first surface 312 a faces the light source 311. The light that isemitted from the light source 311 is incident on the first surface 312a. The first surface 312 a includes a first region 312 e that is curvedin a convex shape toward the light source 311, and a second region 312 fthat contacts the outer perimeter of the first region 312 e and extendstoward the light source 311.

The second surface 312 b is located at the periphery of the firstsurface 312 a. The second surface 312 b is inclined to approach therotation axis C toward the −Z direction. The second surface 312 breflects, toward the interior of the lens 312, at least a portion of thelight that enters the lens 312 through the first surface 312 a. Thesecond surface 312 b corresponds to a total reflection surface.

The third surface 312 c is positioned at the side opposite to the firstsurface 312 a. The third surface 312 c emits at least a portion of thelight that enters the lens 312 through the first surface 312 a. Thethird surface 312 c is a flat surface. In FIG. 12 , the flat surface(the upper surface) of the third surface 312 c is inclined away from thesubstrate 350 toward the +X direction. Therefore, a direction H31perpendicular to the third surface 312 c is tilted at an angle θ31 awith respect to the rotation axis C to become distal to the rotationaxis C toward the +Z direction. Accordingly, the greater part of thelight propagating through the lens 312 is refracted in a directiontilted at an angle θ31 b with respect to the rotation axis C whenemitted from the third surface 312 c. That is, a central axis f31 of thelight emitted from the lens 312 is tilted at the angle θ31 b withrespect to the rotation axis C.

The fourth surface 312 g is located at the periphery of the secondsurface 312 b. The fourth surface 312 g is parallel to the upper surfaceof the substrate 350.

The fifth surface 312 h is a surface that is parallel to the Z-axis andpositioned between the third surface 312 c and the fourth surface 312 g.The fifth surface 312 h is tubular. In other words, the exterior shapeof the lens 312 is circular in a top view.

The driver 360 is capable of rotating the lens 312 around the rotationaxis C. According to the embodiment, the driver 360 includes a motor361, a shaft 362 that moves with the motor 361, a first gear 363 that islinked to the shaft 362, and a second gear 364 that meshes with thefirst gear 363 and is tubular in a top view. The lens 312 is located atthe inner side of the second gear 364, and the second gear 364 ismounted to the fifth surface 312 h. A tooth 364 a of the second gear 364meshes with a tooth 363 a of the first gear 363. The shaft 362 and thefirst gear 363 are rotated when the motor 361 is rotated. The secondgear 364 that meshes with the first gear 363 is rotated by rotating thefirst gear 363. The lens 312 is rotated thereby.

The controller 370 includes, for example, a CPU, memory, etc. Thecontroller 370 is electrically connected to the driver 360 and thewiring parts of the substrate 350. The controller 370 controls theoutput of the light source 311 conjunctively with the driver 360.

In the light-emitting module 300 according to the embodiment asdescribed above, the driver 360 is capable of rotating the lens 312(corresponding to the first lens) with respect to the light source 311(corresponding to the first light source). That is, the central axis f31of the light of the light source 311 (corresponding to the first lightsource) emitted from the lens 312 can be oblique to the rotation axis Cby fixing the light source 311 and rotating the lens 312 itself aroundthe rotation axis C. Thereby, the light-emitting module 300 can berealized in which the light distribution pattern is modifiable.

Also, the light distribution pattern can be modified even when thenumber of light sources is low.

Lens Modifications

In the configuration of the first to third embodiments, each lens is alens that includes a total reflection surface totally reflecting light,and the central axis of the light emitted from each lens is oblique tothe rotation axis so that the third surface, i.e., an emission surfaceof each lens, is oblique. However, lenses in which the central axis ofthe emitted light is oblique to the rotation axis are not limitedthereto. Modifications of lenses will now be described. For easierunderstanding of the following description, examples are described inwhich the number of light source units in the light-emitting module ofeach modification is one, and the rotation axis passes through thecenter of the light source parallel to the Z-axis.

FIG. 13 is a cross-sectional view showing a first modification of thefirst lens.

Paths of the light are illustrated by solid-line arrows in FIG. 13 .

According to the first modification, a first lens 412 is a lens thatincludes a total reflection surface totally reflecting light.Specifically, the first lens 412 includes a total reflection surfacethat totally reflects light inside the first lens 412. The surfaces ofthe first lens 412 include a first surface 412 a, a second surface 412b, a third surface 412 c, and a fourth surface 412 f.

The first surface 412 a faces a light source 111. The light that isemitted from the light source 111 is incident on the first surface 412a. The first surface 412 a includes a first region 412 d that is curvedin a convex shape toward the light source 111, and a second region 412 ethat contacts the outer perimeter of the first region 412 d and extendstoward the light source 111.

The second surface 412 b is located at the periphery of the firstsurface 412 a. The second surface 412 b is inclined to approach thecentral axis g1 toward the −Z direction. The second surface 412 breflects, toward the interior of the first lens 412, at least a portionof the light that enters the first lens 412 through the first surface412 a. The second surface 412 b corresponds to a total reflectionsurface.

According to the embodiment, the central axis g1 is the rotation axis C.The second surface 412 b includes a first perimeter edge 412 t 1 in the−Z direction (the direction from the first lens 412 toward the lightsource 111), and a second perimeter edge 412 t 2 positioned at the sideopposite to the first perimeter edge 412 t 1. The first perimeter edge412 t 1 is the ring-shaped lower end of the second surface 412 b. Thesecond perimeter edge 412 t 2 is the ring-shaped upper end of the secondsurface 412 b and is the boundary between the second surface 412 b andthe fourth surface 412 f. A line L that connects the center of the firstperimeter edge 412 t 1 and the center of the second perimeter edge 412 t2 is oblique to the rotation axis C.

The third surface 412 c is positioned at the side opposite to the firstsurface 412 a. The third surface 412 c emits at least a portion of thelight that enters the first lens 412 through the first surface 412 a.The third surface 412 c is parallel to the upper surface 150 a of thesubstrate 150. The third surface 412 c may be oblique to the rotationaxis C.

The fourth surface 412 f is located at the periphery of the secondsurface 412 b. The fourth surface 412 f is parallel to the upper surface150 a of the substrate 150.

In the first lens 412 of the first modification as described above, theline L that connects the center of the first perimeter edge 412 t 1 andthe center of the second perimeter edge 412 t 2 is oblique to therotation axis C. Therefore, the greater part of the light incident onthe second surface 412 b is totally reflected toward a direction tiltedfrom the rotation axis C. That is, a central axis f41 of the lightemitted from the first lens 412 is oblique to the rotation axis C.

The angle between the rotation axis C and the central axis f41 of thelight emitted from the first lens 412 can be adjusted by adjusting anangle θ41 a between the rotation axis C and the line L of the first lens412.

FIG. 14 is a cross-sectional view showing a second modification of thefirst lens.

Paths of the light are illustrated by solid-line arrows in FIG. 14 .

A first lens 512 of the second modification is a convex lens. The firstlens 512 seals the light source 111. The surfaces of the first lens 512include an upper surface 512 a and a lower surface 512 b.

The upper surface 512 a is a curved surface having a convex shape in adirection (the +Z direction) away from the substrate 150. The lowersurface 512 b contacts the upper surface 150 a of the substrate 150. Acentral axis f51 of the light of the first lens 512 is oblique to theZ-axis. Herein, “the central axis of the light of the first lens 512”means a straight line passing through a position all at which theilluminance of the light emitted from the first lens 512 has a maximumin an arbitrary plane P1 orthogonal to the Z-axis and a position a21 atwhich the illuminance of the light has a maximum in another arbitraryplane P2 that is separated in the +Z direction from the plane P1 andorthogonal to the Z-axis. Namely, the central axis f51 of the light ofthe first lens 512 is the optical axis of the first lens 512.

As described above, the first lens 512 of the second modification is aconvex lens, and the central axis f51 of the light emitted from thefirst lens 512 is oblique to the rotation axis C. In other words, theoptical axis of the first lens 512 is oblique to the Z-axis.

Examples are described in the modifications above in which the number oflight source units included in the light-emitting module is one, and therotation axis passes through the center of the light source parallel tothe Z-axis. However, similarly to the first embodiment, the number oflight source units included in the light-emitting module may be two ormore. In such a case, similarly to the first embodiment, for example,the plurality of light source units may be arranged on a circumferencecentered on the rotation axis.

Modifications of Method for Controlling Light Source Output

Modifications of method for controlling the light source output will nowbe described.

FIGS. 15A and 15B are schematic views for describing a modification ofthe method for controlling outputs of a plurality of light sources.

FIGS. 16A and 16B are schematic views for describing a modification ofthe method for controlling outputs of a plurality of light sources.

The light-emitting module 600 a shown in FIG. 15A includes a first lightsource unit 610, a second light source unit 620, a third light sourceunit 630, a fourth light source unit 640, a fifth light source unit 650,and a sixth light source unit 660.

The first light source unit 610 includes a first light source 611, and afirst lens 612 on which the light emitted from the first light source611 is incident. The second light source unit 620 includes a secondlight source 621, and a second lens 622 on which the light emitted fromthe second light source 621 is incident. The third light source unit 630includes a third light source 631, and a third lens 632 on which thelight emitted from the third light source 631 is incident. The fourthlight source unit 640 includes a fourth light source 641, and a fourthlens 642 on which the light emitted from the fourth light source 641 isincident. The fifth light source unit 650 includes a fifth light source651, and a fifth lens 652 on which the light emitted from the fifthlight source 651 is incident. The sixth light source unit 660 includes asixth light source 661, and a sixth lens 662 on which the light emittedfrom the sixth light source 661 is incident.

The first lens 612, the second lens 622, the third lens 632, the fourthlens 642, the fifth lens 652, and the sixth lens 662 are formed to havea continuous body as one light-transmitting member 685 by being linkedat the surface emitting light. The light sources 611, 621, 631, 641,651, and 661 and the light-transmitting member 685 are fixed to thesubstrate 150.

In the light-emitting module 600 a, the angle between the rotation axisC and the central axis of the light emitted from the first lens 612<theangle between the rotation axis C and the central axis of the lightemitted from the second lens 622<the angle between the rotation axis Cand the central axis of the light emitted from the third lens 632<theangle between the rotation axis C and the central axis of the lightemitted from the fourth lens 642<the angle between the rotation axis Cand the central axis of the light emitted from the fifth lens 652<theangle between the rotation axis C and the central axis of the lightemitted from the sixth lens 662.

Accordingly, the light that is emitted from the first lens 612 isirradiated on a first irradiation region h61 in the plane P3 orthogonalto the rotation axis C as shown in FIG. 15B. The first irradiationregion h61 is a circular region centered on the rotation axis C(restated, a region surrounded with the exterior shape of the firstirradiation region h61). The central axis of the light emitted from thefirst lens 612 moves on a circumferential trajectory e61 inside thefirst irradiation region h61 when the substrate 150 is rotated.

The light that is emitted from the second lens 622 is irradiated on asecond irradiation region h62 in the plane P3. The second irradiationregion h62 is a circular-ring-shaped region that is centered on therotation axis C and positioned outward of the first irradiation regionh61 (restated, a region surrounded with the exterior shape of the secondirradiation region h62 and the exterior shape of the first irradiationregion h61). The central axis of the light emitted from the second lens622 moves on a circumferential trajectory e62 inside the secondirradiation region h62 when the substrate 150 is rotated.

The light that is emitted from the third lens 632 is irradiated on athird irradiation region h63 in the plane P3. The third irradiationregion h63 is a circular-ring-shaped region that is centered on therotation axis C and positioned outward of the second irradiation regionh62 (restated, a region surrounded with the exterior shape of the thirdirradiation region h63 and the exterior shape of the second irradiationregion h62). The central axis of the light emitted from the third lens632 moves on a circumferential trajectory e63 inside the thirdirradiation region h63 when the substrate 150 is rotated.

The light that is emitted from the fourth lens 642 is irradiated on afourth irradiation region h64 in the plane P3. The fourth irradiationregion h64 is a circular-ring-shaped region that is centered on therotation axis C and positioned outward of the third irradiation regionh63 (restated, a region surrounded with the exterior shape of the fourthirradiation region h64 and the exterior shape of the third irradiationregion h63). The central axis of the light emitted from the fourth lens642 moves on a circumferential trajectory e64 inside the fourthirradiation region h64 when the substrate 150 is rotated.

The light that is emitted from the fifth lens 652 is irradiated on afifth irradiation region h65 in the plane P3. The fifth irradiationregion h65 is a circular-ring-shaped region that is centered on therotation axis C and positioned outward of the fourth irradiation regionh64 (restated, a region surrounded with the exterior shape of the fifthirradiation region h65 and the exterior shape of the fourth irradiationregion h64). The central axis of the light emitted from the fifth lens652 moves on a circumferential trajectory e65 inside the fifthirradiation region h65 when the substrate 150 is rotated.

The light that is emitted from the sixth lens 662 is irradiated on asixth irradiation region h66 in the plane P3. The sixth irradiationregion h66 is a circular-ring-shaped region that is centered on therotation axis C and positioned outward of the fifth irradiation regionh65 (restated, a region surrounded with the exterior shape of the sixthirradiation region h66 and the exterior shape of the fifth irradiationregion h65). The central axis of the light emitted from the sixth lens662 moves on a circumferential trajectory e66 inside the sixthirradiation region h66 when the substrate 150 is rotated.

An example in which the light-emitting module 600 a is used incombination with a camera will now be described. The shape of an imagingregion 930 of the camera is, for example, rectangular as shown in FIG.15B.

The controller 170 controls the output of the first light source 611 sothat the illuminance of the first irradiation region h61 is the desiredilluminance. Thereby, for example, the illuminance of the firstirradiation region h61 can be an illuminance corresponding to thedistance to the imaging subject positioned inside the first irradiationregion h61 when viewed along the Z-direction. At this time, thecontroller 170 may set the output of the first light source 611 tofurther include driving parameters of the light-emitting module 600 asuch as the rotational speed of the substrate 150 or the like and/orimaging parameters of the camera such as the shutter speed of thecamera, etc.

The light that is emitted from the lenses 612, 622, 632, 642, 652, and662 is divided into a plurality of subdivisions es1 on the trajectoriese61, e62, e63, e64, e65, and e66 of the central axes of the lightemitted from the lenses 612, 622, 632, 642, 652, and 662. In otherwords, the irradiation regions in the plane P3 are divided into theplurality of subdivisions es1. In FIG. 15B, the trajectories e61, e62,e63, e64, e65, and e66 are divided into the plurality of subdivisionses1 by a plurality of broken lines extending in the radial direction ofa circle. The controller 170 controls the outputs of the light sources611, 621, 631, 641, 651, and 661 in the plurality of subdivisions es1.The light that is emitted from the first lens 612 is not necessarilydivided into a plurality of subdivisions on the trajectory e61 of thecentral axis of the light.

For example, the trajectory e61 is divided into four subdivisions es1;the trajectory e62 is divided into eight subdivisions es1; thetrajectory e63 is divided into sixteen subdivisions es1; the trajectorye64 is divided into sixteen subdivisions es1; the trajectory e65 isdivided into twenty-four subdivisions es1, and the trajectory e66 isdivided into eight subdivisions es1. The plurality of subdivisions es1are set to divide the regions of the trajectories e61, e62, e63, e64,e65, and e66 positioned inside the imaging region 930. Therefore, thetrajectories e61, e62, e63, and e64 that are positioned entirely insidethe imaging region 930 are set so that the lengths of the subdivisionses1 are substantially uniform. In contrast, the lengths of thesubdivisions es1 are nonuniform for the trajectories e65 and e66 becauseportions of the trajectories e65 and e66 are positioned inside theimaging region 930 and the other portions are positioned outside theimaging region 930, and because the subdivisions es1 are set to dividethe portions positioned inside the imaging region 930.

However, the number of the subdivisions es1 and the lengths of thesubdivisions in each trajectory are not limited to those describedabove.

The controller 170 determines the setting values of the outputs of thelight sources 611, 621, 631, 641, 651, and 661 for each subdivision es1.Then, as the subdivisions es1 on which the light emitted from the lenses612, 622, 632, 642, 652, and 662 is irradiated are switched in responseto the rotation of the substrate 150, the controller 170 switches thesetting values corresponding to the subdivisions es1 after the outputsof the light sources 611, 621, 631, 641, 651, and 661 are switched.Thereby, for example, the first irradiation region h61 is divided into aplurality of subdivisions es1 arranged on the trajectory e61, and theilluminance of each subdivision es1 can be an illuminance correspondingto each distance to the imaging subject positioned inside eachsubdivision es1 when viewed along the Z-direction. This is similar forthe other irradiation regions h62, h63, h64, h65, and h66 as well. Atthis time, the controller 170 may set the outputs of the subdivisionses1 of the light sources 611, 621, 631, 641, 651, and 661 to furtherinclude driving parameters of the light-emitting module 600 a such asthe rotational speed of the substrate 150 or the like and/or imagingparameters of the camera such as the shutter speed of the camera, etc.

Thus, in the light-emitting module 600 a, the imaging region 930 can bedivided into seventy-six regions having controllable illuminances byusing seventy-six subdivisions es1.

A light-emitting module 600 b shown in FIG. 16A differs from thelight-emitting module 600 a shown in FIG. 15A in that a seventh lightsource unit 670 is further included, and the light that is emitted fromthe first lens 612 is not divided into a plurality of subdivisions onthe trajectory e61 of the central axis of the light as shown in FIG.16B. The seventh light source unit 670 includes a seventh light source671, and a seventh lens 672 on which the light emitted from the seventhlight source 671 is incident. In the light-emitting module 600 b, theangle between the rotation axis C and the central axis of the lightemitted from the sixth lens 662<the angle between the rotation axis Cand the central axis of the light emitted from the seventh lens 672.Accordingly, as shown in FIG. 16B, the light that is emitted from theseventh lens 672 is irradiated on a seventh irradiation region h67 inthe plane P3. The seventh irradiation region h67 is acircular-ring-shaped region that is centered on the rotation axis C andpositioned outward of the sixth irradiation region h66. The central axisof the light emitted from the seventh lens 672 moves on acircumferential trajectory e67 inside the seventh irradiation region h67when the substrate 150 is rotated.

According to the modification, the angle between the rotation axis C andthe central axis of the light emitted from the seventh light source unit670 most proximate to the rotation axis C is greater than the anglebetween the rotation axis C and the central axes of the light emittedfrom the light source units 610, 620, 630, 640, 650, and 660 that aremore distant to the rotation axis C than the seventh light source unit670. However, the angle between the rotation axis C and the central axisof the emitted light may decrease for light source units more proximateto the rotation axis C. By reducing the angle between the rotation axisC and the central axis of the emitted light for light source units moreproximate to the rotation axis C, shielding of the light emitted fromthe lenses by a housing, etc., can be suppressed when, for example, thelight-emitting module is used as the light source of a flash of asmartphone.

In the light-emitting module 600 b, the controller 170 controls theoutput of the first light source 611 so that the illuminance of thefirst irradiation region h61 is the desired illuminance. Thereby, forexample, the illuminance of the first irradiation region h61 can be anilluminance corresponding to the distance to the imaging subjectpositioned inside the first irradiation region h61 when viewed along theZ-direction. At this time, the controller 170 may set the output of thefirst light source 611 to further include driving parameters of thelight-emitting module 600 b such as the rotational speed of thesubstrate 150 or the like and/or imaging parameters of the camera suchas the shutter speed of the camera, etc.

Also, in the light-emitting module 600 b, other than the first lens 612,the light that is emitted from the lenses 622, 632, 642, 652, 662, and672 is divided into a plurality of subdivisions es1 on the trajectoriese62, e63, e64, e65, e66, and e67. The controller 170 controls the outputof the first light source 611 and the outputs of the light sources 621,631, 641, 651, 661, and 671 in the plurality of subdivisions es1.Specifically, for example, the trajectory e62 is divided into eightsubdivisions es1; the trajectory e63 is divided into sixteensubdivisions es1; the trajectory e64 is divided into sixteensubdivisions es1; the trajectory e65 is divided into thirty-twosubdivisions es1; the trajectory e66 is divided into twenty subdivisionses1, and the trajectory e67 is divided into eight subdivisions es1.However, the number and lengths of the subdivisions es1 included in eachtrajectory are not limited to those described above.

Thus, in the light-emitting module 600 b, the imaging region 930 can bedivided into one hundred and one regions having controllableilluminances by using the first irradiation regions h61 and one hundredsubdivisions es1.

According to the modification shown in FIG. 15A, the light that isemitted from the lenses 612, 622, 632, 642, 652, and 662 is divided intoa plurality of subdivisions es1 on the trajectories e61, e62, e63, e64,e65, and e66 of the central axes of the light emitted from the lenses612, 622, 632, 642, 652, and 662. The controller 170 controls theoutputs of the light sources 611, 621, 631, 641, 651, and 661 in theplurality of subdivisions es1. Therefore, the light-emitting module 600a can divide the irradiation regions into a plurality of regions and canindividually control the illuminances of the plurality of regions. Asshown in FIG. 16A, the light that is emitted from the first lens 612 isnot necessarily divided into a plurality of subdivisions on thetrajectory e61 of the central axis of the light.

Fourth Embodiment

A fourth embodiment will now be described.

FIG. 17 is a top view showing a light-emitting module according to theembodiment.

The light-emitting module 700 according to the embodiment differs fromthe light-emitting module 100 according to the first embodiment in thatthe surface areas of light-emitting surfaces 711 s, 721 s, 731 s, and741 s of a plurality of light sources 711, 721, 731, and 741 aredifferent from each other, etc.

A first light source unit 710 includes the first light source 711, and afirst lens 712 on which the light emitted from the first light source711 is incident. A second light source unit 720 includes the secondlight source 721, and a second lens 722 on which the light emitted fromthe second light source 721 is incident. A third light source unit 730includes the third light source 731, and a third lens 732 on which thelight emitted from the third light source 731 is incident. A fourthlight source unit 740 includes the fourth light source 741, and a fourthlens 742 on which the light emitted from the fourth light source 741 isincident.

The first lens 712, the second lens 722, the third lens 732, and thefourth lens 742 are formed to have a continuous body as onelight-transmitting member 785 by being linked at the surface emittinglight. The light sources 711, 721, 731, and 741 and thelight-transmitting member 785 are fixed to the substrate 150.

Similarly to the first embodiment, each of the light sources 711, 721,731, and 741 includes the light-emitting element 181, the wavelengthconversion member 182, and the light-reflective member 183.

In the light-emitting module 700, the angle between the rotation axis Cand the central axis of the light emitted from the first lens 712<theangle between the rotation axis C and the central axis of the lightemitted from the second lens 722<the angle between the rotation axis Cand the central axis of the light emitted from the third lens 732<theangle between the rotation axis C and the central axis of the lightemitted from the fourth lens 742.

When the substrate 150 is rotated, the peripheral velocity when thelight emitted from the lens moves along the trajectory in theirradiation region increases as the angle between the rotation axis Cand the central axis of the light emitted from the lens increases. Thelight intensity that is irradiated on the irradiation region per unittime decreases as the peripheral velocity increases; therefore, theirradiation region easily becomes dark. In contrast, according to theembodiment, the surface area of the light-emitting surface 711 s of thefirst light source 711<the surface area of the light-emitting surface721 s of the second light source 721<the surface area of thelight-emitting surface 731 s of the third light source 731<thelight-emitting surface 741 s of the fourth light source 741. Therefore,the luminous intensity of the light that is emitted can be higher forlight source units having greater angles between the rotation axis C andthe central axis of the light emitted from the lens. Therefore, theoccurrence of an illuminance difference between the irradiation regionsof the plurality of light source units 710, 720, 730, and 740 caused bythe peripheral velocity difference can be suppressed.

Also, according to the embodiment, in a top view, the surface area ofthe second lens 722 is greater than the surface area of the first lens712, the surface area of the third lens 732 is greater than the surfacearea of the second lens 722, and the surface area of the fourth lens 742is greater than the surface area of the third lens 732. However, themagnitude relationship of the surface areas of the first lens 712, thesecond lens 722, the third lens 732, and the fourth lens 742 is notlimited to that described above as long as the luminous intensity of thelight that is emitted is higher for light source units having greaterangles between the rotation axis C and the central axis of the lightemitted from the lens.

In the light-emitting module 700 according to the embodiment, the anglebetween the rotation axis C and the central axis of the light emittedfrom the second lens 722 is greater than the angle between the rotationaxis C and the central axis of the light emitted from the first lens712. The surface area of the light-emitting surface 721 s of the secondlight source 721 is greater than the surface area of the light-emittingsurface 711 s of the first light source 711. Therefore, the occurrenceof an illuminance difference between the irradiation regions of thefirst and second light source units 710 and 720 caused by the peripheralvelocity difference can be suppressed. This is similar for the third andfourth light source units 730 and 740 as well.

Fifth Embodiment

A fifth embodiment will now be described.

FIG. 18 is a top view showing a light-emitting module according to theembodiment.

FIG. 19 is an enlarged cross-sectional view showing a plurality of lightsource units and a substrate at a cross section along line XIX-XIX ofFIG. 18 .

FIG. 20 is an enlarged cross-sectional view showing the plurality oflight source units and the substrate at a cross section along line XX-XXof FIG. 18 .

FIG. 21A is a drawing showing irradiation regions of the light emittedfrom the light source units at a plane orthogonal to the axis direction.

FIG. 21B is a schematic view for describing a method for setting theangle between the rotation axis and the central axes of the lightemitted from the light source units.

The light-emitting module 800 according to the embodiment includes thesubstrate 150, a plurality of light source units, the driver 160 that iscapable of rotating the plurality of light source units, and thecontroller 170 that is capable of controlling the outputs of theplurality of light sources. The plurality of light source units includethe plurality of light sources located at the substrate 150, and theplurality of lenses that are located respectively as pairs with theplurality of light sources and on which the light emitted from theplurality of light sources is incident. The driver 160 rotates theplurality of light source units in a state in which the substrate 150and the plurality of light source units are fixed. The controller 170controls the outputs of the plurality of light sources conjunctivelywith the driver 160.

The plurality of light source units include one central light sourceunit 890, two first light source units 810, three second light sourceunits 820, five third light source units 830, seven fourth light sourceunits 840, and eleven fifth light source units 850. For easierunderstanding of the description in FIG. 18 , the same unit is shown bythe same hatching.

The central light source unit 890 includes a central light source 891,and a central lens 892 on which the light emitted from the central lightsource 891 is incident. For example, the central light source 891 islocated on the rotation axis C. As shown in FIG. 19 , a central axis f89of the light emitted from the central lens 892 substantially matches therotation axis C. In other words, the angle between the rotation axis Cand the central axis f89 of the light emitted from the central lens 892is about 0 degrees.

Each first light source unit 810 includes a first light source 811, anda first lens 812 on which the light emitted from the first light source811 is incident. As shown in FIG. 18 , for example, the two first lightsources 811 are located on a first circumference c81 centered on therotation axis C. As shown in FIG. 19 , a central axis f81 of the lightemitted from each first lens 812 is oblique to the rotation axis C. Thefirst lenses 812 are arranged so that the angles (angles θ1) between therotation axis C and the central axes f81 of the light emitted from thetwo first lens 812 have substantially the same value.

Each second light source unit 820 includes a second light source 821,and a second lens 822 on which the light emitted from the second lightsource 821 is incident. As shown in FIG. 18 , for example, two of thethree second light sources 821 are located on the first circumferencec81. For example, the remaining one of the three second light sources821 is located on a second circumference c82 that is centered on therotation axis C and has a larger diameter than the first circumferencec81. As shown in FIG. 19 , a central axis f82 of the light emitted fromeach second lens 822 is oblique to the rotation axis C. The secondlenses 822 are located so that the angles (angles θ2) between therotation axis C and the central axes f82 of the light emitted from thethree second lens 822 have substantially the same value, and the anglesθ2 are greater than the angles θ1.

Each third light source unit 830 includes a third light source 831, anda third lens 832 on which the light emitted from the third light source831 is incident. As shown in FIG. 18 , for example, five third lightsources 831 are located on the second circumference c82. As shown inFIG. 19 , a central axis f83 of the light emitted from each third lens832 is oblique to the rotation axis C. The third lenses 832 are arrangedso that the angles (angles θ3) between the rotation axis C and thecentral axes f83 of the light emitted from the five third lens 832 havesubstantially the same value, and the angles θ3 are greater than theangles θ2.

Each fourth light source unit 840 includes a fourth light source 841,and a fourth lens 842 on which the light emitted from the fourth lightsource 841 is incident. As shown in FIG. 18 , for example, two of theseven fourth light sources 841 are located on the second circumferencec82. For example, the remaining five of the seven fourth light sources841 are located on a third circumference c83 that is centered on therotation axis C and has a larger diameter than the second circumferencec82. As shown in FIG. 19 , a central axis f84 of the light emitted fromeach fourth lens 842 is oblique to the rotation axis C. The fourthlenses 842 are arranged so that the angles (angles θ4) between therotation axis C and the central axes f84 of the light emitted from theseven fourth lens 842 have substantially the same value, and the anglesθ4 are greater than the angles θ3.

As shown in FIG. 18 , each fifth light source unit 850 includes a fifthlight source 851, and a fifth lens 852 on which the light emitted fromthe fifth light source 851 is incident. For example, eleven fifth lightsources 851 are located on the third circumference c83. As shown in FIG.20 , a central axis f85 of the light emitted from each fifth lens 852 isoblique to the rotation axis C. The fifth lenses 852 are arranged sothat the angles (angles θ5) between the rotation axis C and the centralaxes f85 of the light emitted from the eleven fifth lenses 852 havesubstantially the same value, and the angles θ5 are greater than theangles θ4.

The plurality of first lenses 812, the plurality of second lenses 822,the plurality of third lenses 832, the plurality of fourth lenses 842,the plurality of fifth lenses 852, and one central lens 892 are formedto have a continuous body as one light-transmitting member 885 by beinglinked at the surface emitting light. The light sources 811, 821, 831,841, 851, 891, and the light-transmitting member 885 are fixed to thesubstrate 150.

Thus, as shown in FIG. 21A, the light that is emitted from the centrallens 892 is irradiated on a central irradiation region h89 in the planeP3 orthogonal to the rotation axis C. The central irradiation region h89is a circular region centered on the rotation axis C.

The light that is emitted from the first lens 812 is irradiated on afirst irradiation region h81 in the plane P3. The first irradiationregion h81 is a circular-ring-shaped region that is centered on therotation axis C and positioned outward of the central irradiation regionh89. The central axis f81 of the light emitted from each first lens 812moves on a circumferential trajectory e81 inside the first irradiationregion h81 when the substrate 150 is rotated.

The light that is emitted from each second lens 822 is irradiated on asecond irradiation region h82 in the plane P3. The second irradiationregion h82 is a ring-shaped region that is centered on the rotation axisC and positioned outward of the first irradiation region h81. Thecentral axis f82 of the light emitted from each second lens 822 moves ona circumferential trajectory e82 inside the second irradiation regionh82 when the substrate 150 is rotated.

The light that is emitted from each third lens 832 is irradiated on athird irradiation region h83 in the plane P3. The third irradiationregion h83 is a circular-ring-shaped region that is centered on therotation axis C and positioned outward of the second irradiation regionh82. The central axis f83 of the light emitted from each third lens 832moves on a circumferential trajectory e83 inside the third irradiationregion h83 when the substrate 150 is rotated.

The light that is emitted from each fourth lens 842 is irradiated on afourth irradiation region h84 in the plane P3. The fourth irradiationregion h84 is a circular-ring-shaped region that is centered on therotation axis C and positioned outward of the third irradiation regionh83. The central axis f84 of the light emitted from each fourth lens 842moves on a circumferential trajectory e84 inside the fourth irradiationregion h84 when the substrate 150 is rotated.

The light that is emitted from each fifth lens 852 is irradiated on afifth irradiation region h85 in the plane P3. The fifth irradiationregion h85 is a circular-ring-shaped region that is centered on therotation axis C and positioned outward of the fourth irradiation regionh84. The central axis f85 of the light emitted from each fifth lens 852moves on a circumferential trajectory e85 inside the fifth irradiationregion h85 when the substrate 150 is rotated.

Also, the number of the first lenses 812<the number of the second lenses822<the number of the third lenses 832<the number of the fourth lenses842<the number of the fifth lenses 852. In other words, the number oflight source units increases for light source units irradiating light onouter irradiation regions. The occurrence of an illuminance differencebetween the plurality of irradiation regions h81, h82, h83, h84, and h85caused by the peripheral velocity difference can be suppressed thereby.

Thus, according to the embodiment, among the plurality of lenses 812,822, 832, 842, and 852, the number of the lenses 812 capable ofirradiating light on the trajectory e81 of the first irradiation regionh81 centered on the rotation axis C of the plurality of light sourceunits 810, 820, 830, 840, and 850 is less than the number of the lenses822 capable of irradiating light on the trajectory e82 of the secondirradiation region h82 that is centered on the rotation axis C andpositioned further outward than the trajectory e81 of the firstirradiation region h81. The occurrence of an illuminance differencebetween the first irradiation region h81 and the second irradiationregion h82 caused by the peripheral velocity difference can besuppressed thereby.

Also, according to the embodiment, angles θ0, θ1, θ2, θ3, θ4, and θ5 aredetermined based on the following Formula (1), where the angle betweenthe rotation axis C and the central axis f89 of the light emitted fromthe central lens 892 is the “angle θ0.”

θk=kα/[2(n−1)]  Formula(1)

Here, n is the total number of the irradiation regions h89, h81, h82,h83, h84, and h85, and is six according to the embodiment. Also, k isthe numeral of the irradiation region when the central irradiationregion h89 is the 0th irradiation region, k increases by one for eachoutward irradiation region, and k is any integer not less than 0 and notmore than n−1. Also, as shown in FIG. 21B, an angle α (0°<α<180°) is theangle between a straight line 931 and a straight line 932, where thestraight line 931 connects a center point, taken to be the intersectionbetween the rotation axis C and the plane in which the light-emittingsurfaces of the plurality of light sources extend, and one point amongtwo points positioned at opposite corners of the imaging region 930, andthe straight line 932 connects the center point and the other pointamong the two points. Accordingly, according to the embodiment, theangle θ0=0 degrees, the angle θ1=α/10 degrees, the angle θ2=2α/10degrees, the angle θ3=3α/10 degrees, the angle θ4=4α/10 degrees, and theangle θ5=5α/10 degrees.

However, the method for setting the angles θ0, θ1, θ2, θ3, θ4, and θ5 isnot limited to that described above. For example, the angle θ0 betweenthe rotation axis C and the central axis f89 of the light emitted fromthe central lens 892 may be greater than 0 degrees and may be less thanthe angle θ1 between the rotation axis C and the central axis f81 of thelight emitted from the first lens 812. In such a case, the angles θ0,θ1, θ2, θ3, θ4, and θ5 may be determined based on the following Formula(2).

θk=(k+1)α/[2(n−1)]  Formula (2)

Here, n, k, and a are defined similarly to Formula (1).

EXAMPLES

Examples will now be described.

FIG. 22 is a schematic view showing a screen, a camera, and alight-emitting module according to an example.

FIGS. 23A and 23B are images captured by the camera in the examples.

FIGS. 24A, 24B, and 24C are images captured by the camera in theexamples.

The light-emitting module 940, the camera 950, and the screen 960 wereprepared in the examples.

The light-emitting module 940 included a substrate 941, a light sourceunit 942, a driver 943, a rotary connector 944, and a controller 945.

The light source unit 942 included a light-emitting element, awavelength conversion member, a light source 942 a capable of emittingwhite light, and a cannonball-shaped lens 942 b covering the lightsource 942 a. The full width at half maximum of the light emitted fromthe lens 942 b was about 15 degrees.

The driver 943 included a motor 943 a, and a shaft 943 b rotatable bythe motor 943 a. The substrate 941 was mounted to the distal end of theshaft 943 b. Also, the light source unit 942 was fixed to the substrate941 in a state in which a central axis f94 of the light emitted from thelens 942 b was tilted 10 degrees with respect to the rotation axis C ofthe substrate 941. At this time, the pair of electrodes of the lightsource 942 a was electrically connected to wiring parts of the substrate941.

The rotary connector 944 was slip rings. The shaft 943 b was located atthe inner side of the rotary connector 944, and rings 944 a of the ringunit of the rotary connector 944 were electrically connected to wiringparts of the substrate 941. Also, a brush unit 944 b of the rotaryconnector 944 was electrically connected to the controller 945 thatincluded a signal generator.

The camera 950 was located at the vicinity of the light-emitting module940. The screen 960 was located at a position about 1 m away from thelight-emitting module 940 and the camera 950 in the +Z direction, andlight was irradiated from the light source unit 942 in the +Z direction.

First, the substrate 941 and the light source unit 942 were rotated at aperiod of 900 ms by the driver 943, and the output of the light source942 a was controlled by the controller 945 so that the light source unit942 was lit for 450 ms each rotation. Then, the screen 960 was imagedusing a shutter speed of the camera 950 of 1 s. The captured image ofthe camera 950 at this time is shown in FIG. 23A. Namely, FIG. 23A isthe captured image of the screen 960 while the light source unit 942rotated about one time.

Also, the screen 960 was imaged using a shutter speed of the camera 950with 2 s. The captured image of the camera 950 at this time is shown inFIG. 23B. Namely, FIG. 23B is the captured image of the screen 960 whilethe light source unit 942 rotated about two times.

From FIGS. 23A and 23B, it was found that light can be partiallyirradiated in a circular-ring-shaped irradiation region centered on therotation axis C by controlling the output of the light source 942 a ofthe light source unit 942 while rotating the light source unit 942emitting light of which the central axis f94 is oblique to the rotationaxis C.

Also, the portion of the captured image of FIG. 23B on which the lightwas irradiated by the light-emitting module 940 was brighter than theportion of the captured image of FIG. 23A on which the light wasirradiated by the light-emitting module 940. Therefore, it was foundthat the illuminance of the portion of the irradiation region on whichthe light is irradiated by the light-emitting module 940 can beincreased by increasing the number of times that the light source unit942 is rotated.

Then, the light source unit 942 was fixed to the substrate 941 in astate in which the central axis f94 of the light emitted from the lens942 b was tilted 30 degrees with respect to the rotation axis C. Then,the light source unit 942 was rotated by the driver 943 at a period of900 ms, and the output of the light source 942 a was controlled by thecontroller 945 to be constantly lit when rotating. Then, the screen 960was imaged using a shutter speed of the camera 950 of 1 s. The capturedimage of the camera 950 at this time is shown in FIG. 24A.

Also, the screen 960 was imaged using a shutter speed of the camera 950of 2 s. The captured image of the camera 950 at this time is shown inFIG. 24B.

Also, the screen 960 was imaged using a shutter speed of the camera 950of 3.2 s. The captured image of the camera 950 at this time is shown inFIG. 24C.

In the captured image shown in FIG. 24A, a portion 991 of a ring-shapedirradiation region 990 is brighter than the other portions of theirradiation region 990 due to the rotation of the light source unit 942.This is because the shutter speed of the camera 950 was greater than therotation period of the light source unit 942, and overlap of theirradiated light of the portion 991 of the irradiation region 990 wasmore noticeable than the other portions.

In the captured images shown in FIGS. 24B and 24C, the difference of theoverlapping light intensity was reduced by increasing the number ofrotations of the light source unit 942, and the unevenness of thebrightness of the ring-shaped irradiation region was less than that ofFIG. 24A. Therefore, it was found that the unevenness of the brightnessof the captured image occurring due to a misalignment between therotation period at which the light source unit 942 rotates and theshutter speed of the camera 950 can be reduced by setting the number ofrotations of the light source unit 942 to be a plurality of, andfavorably three or more, rotations.

The plurality of embodiments, modifications, and configurationsdescribed above can be combined as appropriate within the extent oftechnical feasibility.

INDUSTRIAL APPLICABILITY

For example, the invention can be utilized in a flash of a camera,lighting, an automotive headlight, etc.

This application is based upon and claims the benefit of priority fromJapanese Patent Application 2020-214877 filed with the Japan PatentOffice on Dec. 24, 2020, Japanese Patent Application 2021-190792 filedwith the Japan Patent Office on Nov. 25, 2021, and Japanese PatentApplication 2021-198770 filed with the Japan Patent Office on Dec. 7,2021, and the entire contents of these Japanese Patent Applications areincorporated herein by reference.

REFERENCE NUMERAL LIST

-   -   100, 200, 300, 600 a, 600 b, 700, 800, 940 light-emitting module    -   110, 210, 610, 710, 810 first light source unit    -   111, 611, 711, 811 first light source    -   112, 212, 412, 512, 612, 712, 812 first lens    -   112 a, 212 a, 412 a first surface    -   112 b, 212 b, 412 b second surface    -   112 c, 212 c, 412 c third surface    -   120, 220, 620, 720, 820 second light source unit    -   121, 621, 721, 821 second light source    -   122, 222, 622, 722, 822 second lens    -   122 a and 222 a first surface    -   122 b and 222 b second surface    -   122 c and 222 c third surface    -   130, 230, 630, 730, 830 third light source unit    -   131, 631, 731, 831 third light source    -   132, 232, 632, 732, 832 third lens    -   132 a and 232 a first surface    -   132 b and 232 b second surface    -   132 c and 232 c third surface    -   140, 240, 640, 740, 840 fourth light source unit    -   141, 641, 741, 841 fourth light source    -   142, 242, 642, 742, 842 fourth lens    -   142 a and 242 a first surface    -   142 b and 242 b second surface    -   142 c and 242 c third surface    -   150 and 941 substrate    -   160, 360, 943 driver    -   161, 361, 943 a motor    -   162, 362, 943 b shaft    -   170, 370, 945 controller    -   185, 385, 685, 785, 885 light-transmitting member    -   190, 944 rotary connector    -   310, 942 light source unit    -   311, 942 a light source    -   312, 942 b lens    -   312 a first surface    -   312 b second surface    -   312 c third surface    -   412 t 1 first perimeter edge    -   412 t 2 second perimeter edge    -   650, 850 fifth light source unit    -   651, 851 fifth light source    -   652, 852 fifth lens    -   660 sixth light source unit    -   661 sixth light source    -   662 sixth lens    -   670 seventh light source unit    -   671 seventh light source    -   672 seventh lens    -   711 s, 721 s, 731 s, 741 s light-emitting surface    -   890 central light source unit    -   891 central light source    -   892 central lens    -   910 cover member    -   920 housing    -   930 imaging region    -   950 camera    -   960 screen    -   C rotation axis    -   e1, e2, e3, e4, e61, e62, e63, e64, e65, e66, e67, e81, e82,        e83, e84, e85 trajectory    -   es1 subdivision    -   h1, h2, h3, h4, h61, h62, h63, h64, h65, h66, h67, h81, h82,        h83, h84, h85, h89, 990    -   irradiation region    -   L1 to L4 light    -   f1 to f4, f21 to f24, f31, f41, f51, f81, f82, f83, f84, f85,        f89, f94 central axis    -   θ0, θ1, θ2, θ3, θ4, θ5, θ1 a, θ1 b, θ2 a, θ2 b, θ3 a, θ3 b, θ4        a, θ4 b, θ21 a, θ21 b, θ22 a, θ22 b, θ23 a, θ23 b, θ24 a, θ24 b,        θ31 a, θ31 b, θ41 a angle

1. A light-emitting module comprising: a first light source unitcomprising: a first light source, and a first lens on which lightemitted from the first light source is incident; a driver configured torotate the first lens; and a controller configured to, conjunctivelywith the driver, control an output of the first light source; wherein: acentral axis of light emitted from the first lens is oblique to arotation axis of the first lens; and the controller is configured tocontrol the output of the first light source according to a positionalong a trajectory of the central axis of the light emitted from thefirst lens.
 2. The light-emitting module according to claim 1, wherein:the driver is configured to rotate the first lens with respect to thefirst light source.
 3. The light-emitting module according to claim 1,wherein the driver is configured to rotate the first light source unit.4. The light-emitting module according to claim 3, further comprising: asecond light source unit comprising: a second light source, and a secondlens on which light emitted from the second light source is incident;and a substrate to which the first and second light source units aremounted; wherein: the driver is configured to rotate the second lightsource unit together with the first light source unit by rotating thesubstrate; the controller is configured to, conjunctively with thedriver, control an output of the second light source; and a central axisof light emitted from the second lens is oblique to the rotation axis.5. The light-emitting module according to claim 4, wherein: an anglebetween the rotation axis and the central axis of the light emitted fromthe second lens is different from an angle between the rotation axis andthe central axis of the light emitted from the first lens.
 6. Thelight-emitting module according to claim 4, wherein: an angle betweenthe rotation axis and the central axis of the light emitted from thesecond lens is equal to an angle between the rotation axis and thecentral axis of the light emitted from the first lens; the light emittedfrom the first light source is white light; and the light emitted fromthe second light source is white light having a color temperaturedifferent from a color temperature of the light emitted from the firstlight source.
 7. The light-emitting module according to claim 4,wherein: an angle between the rotation axis and the central axis of thelight emitted from the second lens is greater than an angle between therotation axis and the central axis of the light emitted from the firstlens; and a surface area of a light-emitting surface of the second lightsource is greater than a surface area of a light-emitting surface of thefirst light source.
 8. The light-emitting module according to claim 4,wherein: the first light source unit and the second light source unitare on the substrate at a circumference centered on the rotation axis.9. The light-emitting module according to claim 1, wherein: the lightemitted from the first lens is divided into a plurality of subdivisionson a trajectory of the central axis of the light emitted from the firstlens; and the controller is configured to control the output of thefirst light source in the plurality of subdivisions.
 10. Thelight-emitting module according to claim 1, wherein: the first lensincludes: a first surface on which the light emitted from the firstlight source is incident; a second surface located at a periphery of thefirst surface, wherein the second surface is a total reflection surfacethat totally reflects light; and a third surface positioned at a sideopposite to the first surface, the third surface emitting light enteringthrough the first surface.
 11. The light-emitting module according toclaim 10, wherein: the third surface is oblique to the rotation axis.12. The light-emitting module according to claim 10, wherein: the secondsurface includes: a first perimeter edge facing toward the first lightsource from the first lens, and a second perimeter edge positioned at aside opposite to the first perimeter edge; and a line connecting acenter of the first perimeter edge and a center of the second perimeteredge is oblique to the rotation axis.
 13. The light-emitting moduleaccording to claim 1, wherein: the first lens is a convex lens; and anoptical axis of the first lens is oblique to the rotation axis.
 14. Alens, wherein: the lens is rotatable around a rotation axis by anexternal driver; the lens comprises a convex portion; and the lens isconfigured to emit light having a plurality of optical axes oblique tothe rotation axis by rotating the lens around the rotation axis.
 15. Thelens according to claim 14, wherein: the lens includes: a first surfaceon which the light is incident; a second surface located at a peripheryof the first surface, wherein the second surface is a total reflectionsurface that totally reflects light; and a third surface positioned at aside opposite to the first surface, the third surface emitting lightentering through the first surface.
 16. A light-emitting modulecomprising: a substrate; a plurality of light source units, eachcomprising: a light source located on the substrate, and a lens on whichlight emitting from the light source is incident; a driver configured torotate the plurality of light source units in a state in which thesubstrate and the plurality of light source units are fixed relative toeach other; and a controller configured to control outputs of theplurality of light sources conjunctively with the driver; wherein: amongthe lenses of the plurality of light source units, a number of thelenses configured to irradiate light while being on a trajectory in afirst irradiation region centered on a rotation axis of the plurality oflight source units is less than a number of the lenses configured toirradiate light while being on a trajectory in a second irradiationregion centered on the rotation axis; and the trajectory in the secondirradiation region is positioned outward of the trajectory in the firstirradiation region.